All points that are valid and known - The 4L60 transmission is even phrased as being “derived”.
The X5 has lots of issues - like I said, everyone is pointing me away from it.
I compared it to others in that era and price range, and found it to be the best choice for my wife to drive. Right now she drives a Cherokee (Which is the greatest thing as far as toughness) but she plowed it into a pole. The advanced ABS systems were elemental in this choice.
I compare my 325CI to my old Supras (Like.. 80s old). The vehicles are really similar and I would buy another Supra in half a heartbeat. I had to factor in that the BMW is hard to maintain, but overall easier than my Supra dreams.
The 4L60 predates the X5 by about 15 years. It was never installed in the X5, the X5 had a BMW designed 5 speed transmission that was made by GM France under contract. The two share NOTHING in common!!!!