This always facinates me.
Did you test drive it before you bought it????? It's got 220 hp....and only 220 hp. It's a Hummer, not a race car. Sure it struggles a bit if you pull out in front of someone and need to hit the gas, but if you're you're just driving along, it moves along just fine.
Were ya driving uphill or into 50 mph winds or what?
Don't get me wrong - more power would be nice....but it is what it is.