I towed with a 108-2 and a 165 Franklin, with a fixed climb prop and never
had a single problem. My neighbor actually did the towing with me in the
sailplane. I've only towed my old SZD-36 Cobra and the DG-400 a few times.
Climb rates of 500 fpm were standard towing at 70 mph. Operated out of 2,400
feet of grass at 600 msl.
Used it for about three years and it suited my needs adequately.
With a bigger engine, I think it would be a good tug all around. It's never
gonna compete with a Pawnee, but not many will...a big problem was getting a
337 on the towhook, I do still have the mount and towhook but the paperwork
went elsewhere if you are interested.