Thanks to everyone who responded to this thread.
I took your feedback into consideration and did some more research.
Comparable 4.8is X5's in the tri-county area range from 52K - 61K.
Long story short, I decided to purchase the 05' 4.8is after the dealer came down to 53K and included the BMW extended maintenance program.
I now have perma grin from driving this beautiful BEAST.
I'll post pics later tonight.