As a rule, I like one-time purchases- Reps are an interesting alternative to gens if you don't want to spend big bucks on gens. That being said, I like the reps to last- after all, the better ones while cheaper than the gens, are not altogether cheap- particularly if you are getting the better ones with good Swiss movements, etc... SO I tend to stick w the all SS and Solid Gold rather than plated.
As others have already stated, plating is crap shoot- and regardless of the quality of the plating, one thing is a certainty- eventually the plating will wear off.
-O