It's not nearly a new model in the sense the '06 was. The non-cosmetic changes are pretty slight. The motor isn't "completely different", it's just enhanced a little. Even though the 2010 engine is newer, it doesn't have the added complexity of the super charger, so could very well prove more reliable long term. Also, the lack of dynamic response in the 2010 HSE could very well stave off vibration issues longer.
The external aesthetics are debatable and the changes slight, but the interior is far and away a *net* huge improvement. And I think, given equivalent performance, the interior comfort, appearance, and feel tops the list of importance, since that is where all the time is spent.