i trained on both a katana and spamcan PA28. i only moved from the katana as the school originally had 2, but then sent one away, and it became too difficult to book slots.
katana is quite slippery, so you have to learn to control the speed in the approach, which is a good discipline as far as i am concerned. gave me some hours on a wobbly prop, which is also useful in an all round appreciation of GA flying. i liked the trim system, was easy, fast and accurate. Viz was excellent.
my only real gripe was the small switches, too close together, but other than that a very nice trainer.