My preference is in my sig...
A rewards system is best and most transparent if your payout still comes when the pool finds a block, as long as the pool hashrate is high enough to give miners several daily block finds. It lends to enthusiasm about finding blocks and doesn't hide how Bitcoin works. The rewards system simply determines how the 50BTC block generation reward is split between pool miners, and we want it to be fair and easy. We know that proportional is not an option because it can be gamed by pool hopping.
Geometric formulas that alter or "decay" the value of shares give a level of obfuscation where you can't determine what your shares will earn. A few other pools already have gone to geometric rewards (and PPS with fee), so you wouldn't be offering anything unique by using those. PPS pool ops can be attacked by block withholding. Slush's formula is not perfect and still hoppable. SMPPS you don't have in the poll - good, because it is a PPS, but lowers the reward when the pool gets unlucky (this variability makes it still hoppable).
The only miner complaint (from those who don't understand the system) is "expiring shares". PPLNS, however, also allows for multiple block wins from the same submitted share, so you can be unexpectedly surprised and rewarded by pool luck (on a proportional pool, all shares expire once a block is found, of course). When you submit a share, it will earn you a fixed payout,
1/N * 50BTC, for
any block finds during the next N pool shares after submission. The N number can be set higher than difficulty if users prefer a longer window, so during an unlucky stretch there are fewer shares that expire with no reward, or can be set lower, if users want faster bigger payouts. Any value of N still gives both full-time and part-time miners the same expected reward. (Note: N should not be time-based, expiring after 12 hours for example, as this breaks the payout system by making share value variable and exploitable.) Mining is really a lottery anyway - if you solo mine, for example, every hash that didn't find a block instantly "expires"; when you mine and don't find a block, you really contributed zero work to the pool.
Consider any votes for proportional as coming from the pool hoppers. When the
posting history is in many pools and pool hopping threads, we know they are the pool exploiters. Pool hoppers don't contribute anything by their straw-man argument that they "help find blocks"; the hashrate of the pool doesn't affect earnings (I was very happy with mineco PPLNS even at 80ghash). When everyone but the pool hoppers leave, there will be one last time that the pool crosses 43% of difficulty shares, and then it will be dead.
PPLNS worked very well on mineco. It doesn't have any pool-op risk requiring extra fees. Miners still get joy when a block is found.
I thought Clipse's was paying 115%
