In the long run, the 4.8 might also be a better b/c:
1)resale value might be better b/c it has the current face lift.
2)Not really sure, but there might be a small difference in gas efficiency.
3) You will probably will have less problems with an unmodified car.

I currently drive a 4.8 and love it more then anything else...to the point where I can't find any else worthy since I am looking for a second car for the family

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Lemans Blue X5 4.8is
Dynaudio
Diamond TDX 12" subs x 2
Xtant X604 x 2
Xtant X1001 x 1
VST 7" LCD x 2