Before I begin, let's make sure that we're defining our positions accurately.
I merely stated (#6845), regarding why the Eastern Orthodox Church uses the Septuagint: "If it's good enough for the Apostles, it's good enough for the Apostolic Church"
That defined the issue. I stand by my statement.
The New Testament quotes from the Septuagint in 93% (other sources claim 95%) of the time. I would say that defines my answer, and corroborates my emphatic statement that what was good enough for the Apostles is good enough for the Apostolic Church.
Of all the instances where Old Testament quotes in the New Testament favor the Hebrew version is exactly six!.
The impressive comparison of NT agreement with the Septuagint when it comes to OT quotes, and an equally impressive departure from it based on the Hebrew text (used by the Jews and the Protestants) should make every Protestant wonder if they are reading what the Apostles wanted us to read.
The source you site indicates the following Apostolic NT authors' OT quotes agreeing with LXX, according to books, expressed as percentage:
Matthew 83.3
Mark 88.9
Luke 92.3
John 92.9
Acts 100
Romans 94.3
1 Cor 88.2
2 Cor 100
Galatians 100
Ephesians 100
1 Timothy 100
2 Timothy 100
Hebrews 97.3
James 100
1 Peter 91.7
2 Peter 100
Total 93.0
I would call that A+/A in most cases.
By comaprison, the Hebrew rendition of the OT agrees significantly less with the Apostolic inspired choice of LXX:
Matthew 70.4
Mark 85.2
Luke 80.1
John 71.4
Acts 75.0
Romans 58.2
1 Cor 70.6
2 Cor 80.0
Galatians 60.0
Ephesians 100
1 Timothy 100
2 Timothy 0
Hebrews 54.1
James 75.0
1 Peter 41.7
2 Peter 100
Total 68.3
I would call that pretty poor, C/C+ on average, and a clear F in some cases!
Surprisingly, the author does not list Isa 9:6 as significant differences between LXX/MT.
In the KJV version: v.6 For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God, The everlasting Father, The Prince of Peace.
(This you shall find in the Alexandrian version of the LXX as well, which in this instance agrees with the Hebrew version).
But the Sinaiticus and Vaticanus versions have this:
v.6 For a Child is born to us, and a Son is given to us, whose government is upon His shoulder; and His name is called The Messenger of Great Counsel; for I will bring peace upon the princes, and health to Him
Quite different in tense (underlined), message and content (bolded).
likeswise, v.8 in KJV says "The Lord sent a word into Jacob, and it hath lighted upon Israel."
In the older versions of the LXX it says "The Lord has sent death upon Jacob, and it has come upon Israel."
The choice of words is amazing! Now, how did these discrepancies 'sneak' in if not by (1) copying errors, (2) different sources, (3) translational errors, (4) missing accents, (5) deliberate alteration of what the scribe believed should be... etc?
Of course the errors of one side will be multiplied by other sources using the same or similar language (i.e. DSS and MT), so the 'corroboration' of the DSS with the Hebrew text, since DSS are also in Hebrew, is not surprising, but rather expected.
Thus, the uncertainty. The only thing we can be certain of, when reading the Scriptures, is that we are not certain if we are reading the the correct version (whichever that may be).
As for the agreement between the LXX/Greek and MT/Hebrew, here is a chart (using your own source from #7180)
The Apostles, in their wisdom, based on their choice to overwhelmingly use LXX, are clearly telling us that the Truth, as was known to them, is contained in the LXX to a much greater extent than the MT. (Somebody please tell this to Luther!)
But, as far as the Apostolic Church is concerned, the message is loud and clear: the Apostles wanted the world to know what LXX says when it comes to those passages of the Old Testament the Lord and they deemed appropriate for Christian mindset. In 93-95% of the cases.
I stand by my statement. And I stand by mine: If the Apostles were, however occasionally, finding it necessary to correct the LXX, it meant that they were checking it against the Hebrew texts available to them, which may or may not have been Masoretic. And if they were double-checking the LXX, it wasn't "good enough" for them in the sense that you feel it is good enough for you--they used it only where it was in agreement with the Hebrew text (not necessarily from the tradition that gave us the Masoretic) or clarified the Hebrew text for their Greek audience.
But did they consider it God-breathed? If they had, they would have never corrected it--one does not correct the words of God.
The New Testament quotes from the Septuagint in 93% (other sources claim 95%) of the time.
Misleading statement, since you fail to take into account the number of times there is no significant deviation between the LXX and MT for the authors to actually choose between. The author of the site I used for a resource fails to make this distinction as well, though we can derive somewhat from his numbers.
He claims that the NT quotes from the LXX 93% of the time and is in agreement with the MT 63% of the time. That means that even by his count, that 56% of the time there is no difference for the NT authors to choose between--and hence no indication of preference. That means that in passages in which there is any difference between the two readings, the LXX is being chosen 37% of the time and either the MT or the author's own translation of the Hebrew 7% of the time by his count, a ratio of about 5 to 1. Certainly that favors the LXX to a large degree, but not by the 93% to 7% that he implies!
Moreover, I think his counts are flawed. Unfortunately, he does not show all of the passages in which he finds deviations in favor of the LXX, and the 30 he presents only amount to about 10% of the NT quotes (which number from 280-300 depending on who is doing the counting--one source says 287 direct quotes, and since I'm not going to go through and count them, I'll use that figure for our discussion), or about a third of those he claims deviate. Let's assume for the moment that this is a representative sample.
Now, let's first strip out those quotes in which there is no actual disagreement in the MT, just a debate about the translation:
Isa. 7:14 - As mentioned, almah does in fact mean virgin (or the closest Hebrew word to it), so this is not actually a descrepancy. Psa. 8:2 - The phrase erroneously translated in the author's example "founded a bulwark" is yisadta oz. Yisadta means "establish" (just as it is rendered in the LXX), while oz, while meaning "strength," can be used in the sense of "splendor," "majesty," or "praise," as it is in Psa. 29:1 (see the Thayer's Lexicon entry here). So again, there's no true disagreement; only a question of a translation choice.
Amos 5:25-27 - The phrase "Sakkuth your king" (Sakkuth melek'khem) can also be translated, with a different set of vowels (which were not added until well after Yeshua's time) "the tent of your Molech." So there's no real difference there; just a translation choice.
For Kiyun, this was the Assyrian name for the deity we commonly know as Saturn, who was in Coptic called Remphan. Since the LXX was rendered in Alexandria, it's hardly surprising that they decided to "update" the name to one the Egyptian Greeks would have actually heard of. In any case, there's no contradiction here, just another translation choice.
Isa. 53:7-8 - The website's author actually botches this one, since the quote is actually all from v. 8, which in an extremely woodenly literal translation of the MT Hebrew, reads, "From prison and from justice He was taken; and of His generation who will consider? For He was cut off from the land of the living."
The word translated "from prison" is mae'otzer, with otzer meaning "oppression," and that of a sort to bring about humiliation, as a barren womb brought to a woman (cf. Pro. 30:16)--hence the decision of the LXX translators to render it tapeinusei, a lowly estate or condition. Likewise, in this context, being taken "from judgment/justice" means the same thing as the literal translation of the LXX krisis antou erthe, "from His justice He was lifted away." Again, no distinction if one is actually referring to the LXX itself and not to a bad translation that makes a mountain out of less than a molehill.
I'm going to stop there for the time being, since it's late and I'm weary of looking up the original words in the original languages to compare meanings. Suffice to say that in many of the author's examples, there's no actual difference between the quotes--unless one is merely comparing two English translations. In other cases, which I've not even started into yet, the difference in translation amounts to a dynamic-equivalent translation choice that doesn't affect the meaning of the passage but might clarify it to a Greek audience (e.g., Isa. 8:17 or 29:13). In other cases, like Deu. 32:43, while the quote is not found in the MT, it is found in the DSS.
By the time you remove these passages, the number of times the NT agrees with both the LXX and the Hebrew text closes the gap substantially. The LXX probably does still "win," but the fact that the Apostles did correct it indicates that they were continually checking it against the Hebrew original and deciding on a case-by-case basis whether to use the default Greek translation of their day or render their own translation.
'Nuff said for now. I'm off to bed. Goodnight (or good morning by the time you read this, probably), and God bless.