Pace,
Well, using my incorrect user name after having been put right before is either deliberately insulting or careless ignorance! I feel very insulted!
Personally I would agree that a conversion for an experienced pilot from Piper to Cessna should need very little, but I think in real life you will be hard pushed to find a club that will NOT require a full hour conversion as a minimum. For inexperienced pilots most DO need this and I think your experience might blind you to how poor some can be! I did point out though that most schools should be able to do the conversion WITH the club checkout. More realistic for a Pa28 pilot would be to do an hour checkout with conversion and then a few circuits to satisfy them you are still ok on the Pa28.