When I was looking at buying an X5 last year, I called around a few independent mechanics in my area. They all suggested that 3.0 would be more reliable and less problematic than 4.4 ("definitely get a 4.4 with extended warranty" they ALL said.)
I have been on this forum for the last year perhaps, and every new thread that comes up with regards to transmission issues during my time here, has been from a 4.4 owner. (I eagerly look at these threads since, without an extended warranty, I would like to know what kind of signs/etc. I need to look for ... and I realize the thread is about a 4.4 and not a 3.0... this has happened in many threads... I may have missed one or two here and there... but I would say a good majority of them while I have been on this board have been about a 4.4.)
The 4.4 obviously has better performance and is a much better 'driver's' car than 3.0 will ever be. It may have more problems/maintenance to go with that better performance... if you are after that kind of performance, pay to play and enjoy the performance.
Now that I have said the above, obviously my 3.0's transmission is going to disintegrate and explode on my way home tonight. It will serve me right.
