Having all the alternates is NOT essential. They do differ from track to track but listening to all these in a row can be tedious.
This is among my favorite Pepper however, so I'm glad to have them myself; what I do often with collections like these is program the first alternates to listen to one time, the masters another time, the second alternates the next time, etc. But you may well be served by the one cd from Atlantic/Savoy. Or those two separate older cds, which have slightly better sound (in my opinion at least).