Every Cardinal owner I know is tickled pink with their aircraft. The RGs go along at a stink -more than 130 knots I think. And that front undercarriage door is one hell of an airbrake!
However, I do disagree with the poster who talk about RG issues on grass. I fly a 182RG of a very short grass field and have had no problems whatsoever for a number of years.
I think the only issue with the Cardinal RG I know of is that if you thump it down heavily, you sometimes need to have misaligned downlock microswitches sorted out. I know of two who've needed to do that.
A super aircraft which in my view is the prettiest high wing single (he said, waiting for the inevitable catcalls from the Piper fraternity!)