Rooster....DO IT....I had an h3, went to an H3 Alpha (which I still have) and then picked up an H1 also and I love it. Its definitely is not as road friendly as my H3, the H1 is sluggish for sure on the highways and it has a lot of mass passing and stopping quickly are not an option its a different driving style. that being said I love it and the inconveniences that it has in that aspect are part of what make me love the car. Tech wise (I have an '03) I've had an air conditioning compressor break needed to be replaced with a new one, and needed a new circuit or something like that for the fan selector. I believe I have a coolant leak and a CTIS front leak, I'm not a tech savvy guy so I don't know how to fix these myself so I'll be taking it for those problems too. However what can I expect from an 11 year old truck to have a few problems. All part of the game.
As for tech questions compared to model years this is a great site to look at it, you can see about the 94's and read about the other years as well to help make an educated decision.
http://www.lynchhummer.com/Changes/h...ges.index.html