I have a model 23 (91) that is the same as the 2720.  I've towed it over 3000 miles in the last year with a Dodge Grand Caravan with a 3.3 engine and towing package.  I also have an equalizing hitch and anti sway bar.  I can easily tow it at 60-70 mph and even use overdrive on relatively level ground.  My son is a Chrysler transmission repairman so I had him check the tranny after both of the first two long trips.  He found nothing to indicate that the transmission was under undue stress, no metal shavings, worn discs or even burnt or discolored transmission fluid.  The early Chrysler transmissionss had some serious problems, but they got significantly better in 93, and by 96 it wasn't unusual to see them with over 150,000 miles before repair.  I've owned 4 of these minivans and have put over 250,000 on each of the first three and have 65,000 on my 2001!
    We are careful how we pack and typically don't travel with full water tanks and load as evenly and pack as lightly as possible.  By the way, the recommended max. for this vehicle is 3800 lbs, and I try to stay at 3000 or less.  Hope this helps, Denny    (By the way, 18 mpg at 55-60, 14-15 at 65-70)