[Wisha Haddan H3]

The only significant difference right now is the engine. The low end torque/HP is the same. You only see the extra torque/HP at the high end ... which is good for passing or mountain roads. But it also has improved oil delivery and a clutched alternator for lower noise and similar mpg. 2007's also got a beefier sounding horn.

If you wait a couple more months, a new door panel comes out with a better window switch location. And they will have a fix for the highway vibration some people get in their marker and offroad lights.

There have been some incremental quality improvements since the first model rolled off the line, but it's hard to say if a 2006 will have a particular problem. For example, faulty rear wiper, poor fitting and cracked roof rails (GM has a new supplier now), excess lapping compound on diff gears, insufficiently hardened diff gears, faulty heads on the 3.5L (pretty rare but possible) ... all covered under warranty. Can't think of any more right now. You can check some problems by date (with a VIN).

fwiw, in the late 2006 and 07 models, they added an extra cubby in front of the automatic shifter for change or sunglasses, but took out the console tray insert (except on lux models).

Whether you get an 06 or 07, ask for the latest flash updates for the computer. GM added a few updates for the idle, shift points, wiper delay and other things.