I was going to be flying one just before I was picked up for the jet job.
The owner speaks very highly of his, and says it's a good trainer. You might have to take into account that we don't have a real problem with high density altitudes in Pennsylvania, and your area may present different concerns.
The Cougar reminded me of an Aztec. If it flys like one, you should be okay.
I instructed at a flight school that had two Cougars for multi-enginge training and I logged a couple of hundred hours instructing in them. The Cougars are a really good training airplane and a real nice airplane in general. If you have any specific questions about them I will answer them to the best of my recollection.
I also logged about 60 hours in a friend's Cougar. Anywhere we went the controllers would ask us about it. None of them had ever seen one. I think they only built like 120 and there like 70 or so flying in the US. But a good, stable airplane. Easy systems....and you can't beat it on 16 gph(or something like that).
I have all of 1.4 hours in a Cougar (it was taken off leaseback a week after I started flying it), but I can say that I loved the little time I spent in it. It performs like a Duchess on 20 fewer horses per side. The owner said that it can sometimes be hard to find parts, although overall it's been a reliable and cheap airplane to own.
It handles well - a little lighter on the ailerons than the Duchess. VERY comfortable cabin, and the panel has a styling that makes you feel like you're flying a much bigger plane than you are. Easy to land, and easy to fly. If you can find one in good shape - I think it'd be a good deal.
You might see more of those planes flying around. I read somewhere that Socata (Tampico/Trinidad/TBM, etc) had bought the plans for the plane and might restart production. They plan on putting those new Renault diesel engines on them and calling it the Tangara. Haven't seen any new info about it, though.