The Aircon on the 156 isn't the best, but there isn't much differance between the previous model and the new one, the Duel Zone control adds a bit of complexity but the venting and cooling is about the same. Don't think the vents are bigger, in fact I would say they are smaller.
Radio reception on both my 156's, (yr 2000 2.0TS, and 03 JTS) has been OK, but I did have courtesy Car once which was Crap, so I think it can be variable.
My experiance is on the 02-03 facelifted Cars, not the newest ones which have had the nose job.
I don't know if they are differant to mine or not.