5% is still okay in my book, but that's about the limit. LiteGuardian does 2% PPS, and it's not doing any hybrid.
The reserves a pool needs to handle the swings of PPS are too much for it to be a consideration. Combine that with the block withholding attack risk that can drive the pool bankrupt it's not worth it.
I like mmpool with or without PPS, I'm just giving my opinion on PPS in general.
Oh, well yea, I agreed with you 100% with PPS in general.
Personally, I think PPS rates should be trailing; based on the pool's average rate at which they find blocks for one Difficulty Term.
I would first set my break-even, minimum PPS %, then choose an arbitrary number + % as the first control term. After the Network Difficulty adjusts, get the avg. Time between blocks on network and between blocks found in pool. I would see how the pools avg. Hashrate changed +/- then adjust the PPS n% higher, or lower.
Of course you would need an upper bound limit pool miners would agree too, but adjusting the PPS between let's say 1.25% and 5.05% could average out nicely for Pool managers and Devoted Miners.
My math is 'Pseudo Math' I would need time to write an actual formula, but that's my idea.
PPS with a variable fee based on luck. Interesting.