Here's the problem I had with the 3.5-litre I5:
In the Colorado, it moved it along in a way that could best be described as 'sufficient'. It wasn't bad, but it wasn't great. Quite frankly, I wouldn't want to have to live with one with that engine for any great length of time, but there are worse options.
In the H3 (which gained somewhere in the region of 700-1000lbs. of glass, metal, and mechanicals over the Colorado, depending on spec), it was a complete and utter gutless wonder in anything other than 4LO - and even then, the only reason it worked as well as it did was because of the 4:1 low range.
We had one on test in (IIRC) May of last year. The H3 did great off-road, but with three of us plus (maybe) 100lbs. of camera gear in it, it took 18 seconds for us to pass a 1990-ish Geo Metro doing 75 on an uphill stretch.
I'm willing to admit that I haven't yet driven a vehicle with the 3.7 in it, so my comparison may be a bit dated - but I still stand by my assertion that the 3.5-litre I5 is comparatively down on power.