I've got an auto, picked it up 2 yrs ago. Stock then with 225's and 3.73 in the 97. Sluggish back then. I did notice that it locks/unlocks the tc during highway speeds. Hit the brake and it'll upshift 3-400rpms. Not enough for the 4cyl to reach its higher hp rpm, but still bumps the torque band pretty good in the 3200rpm range. I think the 4cyl hp rpm is 4500-4800 as I usually had to run into 2nd to get enough momentum to drive pass someone. My TJ is not a dd, but optional. Its what I drive to the trails and back from the trails.
Now its geared at 4.88, turns 34" LTBs, running a TBI spacer, and upshifts into 2nd before 5mph. It's there till about 30 then goes into 3rd, up to 65-70 an hour later. Its a slug for sure. Best mileage I got was 15 at 1 time. Normal is 11-13mpg (yah really need the gas filler tube mod). I usually control the shifting manually and get up going that way. I do hit the 5200rpm mark on the highway but for a short period of time when I want to get around an idiot. I recently installed the spacer so that has affected the take off scenario, but highway, there is power in them higher rpms. As for off-roading, auto works for me with the gear ratios I've got. I'm working on getting a doubler low setup for better low speed crawl. Too bad there is nothing for the high side of the system. I would like a 1.4 for that.
Overall, I would like a 6cyl, but cheap Jeep is a cheap Jeep.