After instructing for about 30 years I gave it up four years ago, so my opinions may be somewhat out of date. I don't know if it is still available, but I thought the Midwest Aerostar 40 built  from a kit was a great trainer. I flew dozens of them and only one didn't fly well. Never did figure what was wrong with that model, but the student only showed up one time. At our field the current instructors seem to fly the ARF's with the "gimmicks turned off.' The Mustang and Raptor PTS have a bad reputation here; other than that they are all very simmilar.