your 2003 and 2011 are very similar to the hummer drivetrain. except the hummer has all time 4 wheel drive so fuel economy will not be as good as the 2 vehicles you currently own. as for the transmission they do go as you have experienced. but i am sure if you had the ability at the time to fix the one in your 04 it would have lasted you for quite some time till the brake lines gave or the fuel pump top rotted. mostly happens in the north east or where they heavily salt. so something to look out for.

 

I have an 03 suv and 08 sut. The first gen are very much the same as a Tahoe/suburban/etc. if you are good at repairs find a high mileage one for under $10,000 and have fun. If you want a more refined hummer go with the 08-09. But with these models there are not as many interchangeable parts and it makes them even more expensive to keep up with. For example my 2003 has the old school hydroboost system for the brakes GM has used it since the 70s, repairs are fairly easy, my master cylinder started leaking on the 08, and cost $850 to replace as the unit was only made for the 08-09 h2 and includes the master, electric booster, and the abs module. If you look at replacement interior pieces you will see the difference between the two for parts. The 08 drives like a little sports car but the 03 is pretty tough and easy to grab parts for. Just my $.02. Thanks