I own an SUV, non-Volvo, and except for being able to see around all of the other SUVs on the road, consider it to be a huge waste of money. Having 7 seats was the primary reason for purchase, but when the rear seats are being used, there is almost no room for carrying luggage.
The high profile eats into gas mileage, the extra weight requires more BHP to get to 60mph, side winds here in the Midwest will push the SUV around more than a wagon.
The T6 engines generate too much heat for the electronics in the engine compartment, and the higher BHP does a number on the tranny trying desperately to move all of the weight. The 3.2L engines are cooler and easier on the tranny without the sudden onset of torque that the T6 produces at 3K rpm.
IF you must have an SUV, check out all of the others in the market and compare them to what you need.

Klaus
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Proud owner of a 1967 220S. If I had more room, I would have more Volvos.

Here's a similar thread from a few days ago:

http://www.brickboard.com/AWD/volvo/1378700/xc90_yearstypes_avoid.html

I've heard the newer ones have gotten better; my uncle owns a 3.2 non-turbo, not sure what year. It's NOISY, but overall a really nice car. Several others from that thread recommended staying away from the T6's and sticking with the tried & tested T5 engine & transmission combo that has been in other Volvo's since 1993.

Hope this helps!