Check out Fr. Z at What Does the Prayer Really Say?
He has done this weekly column for the last few years, covering the official prayers in the Mass for each week (The first year he did the opening prayer, the second the "prayer over the gifts." This year he is doing the post-communion prayer.) It is quite clear that much is lacking in the official translations, especially where ideas of grace or sacrifice are encountered.
We deserve much better, more-faithful-to-the-text translations.
As an example, here is the last one given on the website, for the second Sunday of Lent:
LITERAL TRANSLATION: (done by Fr. Z)
As we are now grasping, O Lord, the glorious transforming sacrament,
we are busy offering thanks to you,
for you are granting us, placed here on earth,
to be participants of the heavenly mysteries now at this very moment.
ICEL (1973 translation of the 1970MR): (what we hear at Mass)
Lord,
we give thanks for these holy mysteries
which bring to us here on earth
a share in the life to come.
This is not a particularly egregious translation, the basic ideas are there. But still, a side-by-side comparison shows that we are not getting anywhere near the full ideas expressed in the Latin original of the prayer.
SD