I have only flown a Grob 115 once. It was the 115 HP one. The place in Florida that had them had two of that config and one 160 hp one, which was in the shop. Seemed like a nice airplane. The one in the shop shedded its tail after it was back online, two people died, and they went back to cessna. I would disagree the higher HP airplane is the better trainer, just as a generality. A low powered trainer demands more finesse from the student and this is important.
For helicopters, I learned in an underpowered Enstrom F28A and liked it very much. Great for full autos, low powered, manual throttle. I flew a few CB300's, very nice machine, but over on rotorheads it sounds like folks are having problems getting parts. That is a shame.