I just made some edits , everyone no matter their individual hash rate gets the same payout. This is why minimum hash rate to join is very important.
A pool which guaranteed the exact same payout to all members, regardless of hash rate, will attract members with the lowest possible hash rate and deter potential members with higher hash rates. Say you're the operator of this hypothetical pool, and you set a minimum hash rate of 300 MHash/s - that keeps out miners with anything slower than one 5870, but equally someone with one or more 5970s will prefer to use a different pool - what's the point in using your pool if they're guaranteed to get paid the same as a miner using only a 5870? Might as well use a different pool and get paid more.
Your proposal would work, but it would have the side-effect of limiting pool membership to owners of one particular GPU. Personally, I'd prefer to belong to a big pool (i.e. one that doesn't limit membership) as the payouts will be more frequent.
Ok over 200mhash/s may be too high for now.
I just feel like there has to be a better way to run a pool. What about 10 tiers , starting at 50mhash up to 500mhash in increments of 50 so you would attract the larger range of users. The tiers each having higher payouts as you go up so not to turn off the more powerful users, but each whichever tier you are in you will get the same as everyone else in that tier. Maybe I am getting ahead of myself considering I am new here but I think if a few people put their heads together we could come up with something more attractive and efficient than the current pool models. The eventual goal will not be to have the largest pool, but the most powerful pool with a smaller amount of members.
If anyone would like to actually work on creating a completely new model for a pool , whether you like my ideas or not , ,let me know, it is worth a shot.