Considering a 2006 CPO X5 4.8is

[SoCal_M3]

I've never been an owner of an X5 yet. I'm considering a new (09 4.8i) or used (2006 4.8is). Is the 2006 4.8is motor essentially the same as the one in the 2009's? I recall when they started with the 4.6is, someone else built the motor (Alpina maybe).

Can anyone give me a reliability/quality perspective on the 2006 4.8is? I tend to keep my BMW's a LONG time (200K miles). I realize BMW's aren't the cheapest to maintain, but they're worth it. Just want to ensure I'm not getting into a mess if I bought the '06 4.8is.

Thanks in advance.