I had 3 Jeeps (two 05 Wranglers Rubicon TJ/Sport LJ and an 04 Grand Cherokee 4.7L V8), the 4.0L was a good motor, but 180/190HP is all it'll do. The 3.7L I5 is 242HP and the H3 has 4.56 gears vs a wranglers 3.07/3.73/4.10. The 4.0L is awesome under 65MPH or off road. The H3 is good on/off road. I have no problem going 80-85MPH on the freeway if needed in my wife's 07 H3. In both my 4spd auto's TJ/LJ keeping up with traffic in the 70-75MPH range is a true struggle.
The 3.8L is a true piece of junk!! Nothing will ever make that minivan 3.8L a good choice in a Jeep. The 3.6L is much better in the HP department, but OMG the electronic throttle response is just awful. I love my Alpha's 5.3L, but I have zero issues with the 3.7L I5!a
Jeep people are biased these days and I honestly can't stand em... Sad but true. If you don't have an AEV rig or a Smittybilt rig you're nothing to them lol.
After owning both I'm extremely happy with the H3 and I'd never go back to a Jeep. Oh and the HVAC is ice cold vs the Jeep's cool breeze lol.