How are they on long trips 1000 mile+??
My M998 can only do 55 mph top speed. Well it can do more, but the drive train system can't handle it. The HMMWV isn't like the Hummer, it wasn't designed for long road trips. You actually have to pull over alot and let all the hardware cool down from time to time. If you wanted to do go somewhere far away and do off-roading your actually suppose to flat deck it to the location. Don't get me wrong, I rather off-road with a HMMWV then an H1 if given the choice because it was a truck designed for off-roading and nothing but off-roading, in fact it can actually out-preform an H1 off-road for a number of reasons (depending on the situation).
HMMWV's (the older versions) were made lighter, simpler then the H1 (not to mention all the parts are waterproof and can be completely submerged underwater up to the snorkel and exhaust pipe). H1's have all kinds of things in it that are designed for comfort and coolness which take away from it's reliability (such as finished interiors, electronic vehicle operation things, parts not made to military/reliability specifications). All of these factors determine how the trucks function. The H1 is a good off-road vehicle and a diesent on-road vehicle, but the HMMWV is by far a great off-road vehicle and totally crap when it comes to putting them on the road (you just have to treat it like an aircraft and not like a car in order to get the most out of it and properly maintain it).
To all the H1 fan's out there that read this...don't worry, I love H1's to and I'm still planning to get one to go with my M998 when I get the money