I had an 07 h3x for a couple of years and love it. Sold it a few months ago and got my self an 05 H2 SUT and LOVE IT EVEN MORE. I told my wife that I dont think I could drive anything else........

 

If your going to be towing on the heavy side (up closer to 9,000 lbs.) then you probably want to look at 2008-2009 H2's. With the 6.2L/6 speed it tows much better than the 6.0L/4speed. We went from a 2006 to a 2008 last year and the difference in power and towing is amazing. I towed my friends 32' Offshore boat which has 2 bigblocks and sits on a triple axle trailer. With the boat, trailer, 120 gallons of fuel on board and gear we estimated the total trailer weight somewhere in the 8,500-9,000lb range..... towed it without issue and didnt feel underpowered. In my 2006 I towed a heavy equipment trailer with my Z06 on it, total weight estimated around 6,000lbs and while it pulled it good you could certainly feel it on the back.

As far as reliability...... other than a few minor annoying items that were finally fixed under warranty (nothing major).