I agree, keepers can bring up too many problems. The only way, I feel, that a keeper is worth while is if you know your other league mates and they are all in it for the duration and they are all knowledgable owners. Really, alot of IFs. I prefer redraft leagues because of all these IFs. That, and I haven't been able to get 12+ owners that I know are knowledgable and competitive.
I would also would prefer that 5 be the MAX amount of keepers because I think draft day is probably the best part of fantasy and if you keep any more than that then the draft is only half of what it could be, IMO.
Anyway, give me a redraft league 98% of the time. My favorites are 14-16 team mixed or 10-12 team "only" leagues.