I'm not sure why, but this pool seems to have lower earnings than slush's pool. after crunching some data from slush's pool, i found out that i make around 0.03 BTC per hour mining. However, i ran a miner for 1 entire day, and the "estimated earnings" is only 0.06 BTC.
slush's pool and our pool use completely different scoring mechanisms. We pay based on an equal proportion system.
Your payout = the number of shares you submit / the total number of shares in the round
slush's pool is weighted shares, where as the round progresses, the newest shares hold the highest value, and older shares slowly lose value.
There are other factors that can also be reflected in observed payout, such as the number of shares submitted over X amount of time, the askrate being used, on what miner, speed of the card/cpu, etc...
Observing for even a few hours is likely too small of a dataset to determine actual results, since your payout is also based on those same factors for everyone else on the pool. Your card may have been finding shares at a slower rate, just getting a lot of getworks that didn't have answers, while someone else's card may have been having the opposite occur, which would reduce your payout as the total number of shares for the round increases, and your submitted shares stayed the same.
We tested our pool based on datasets of two weeks of constant mining from either pool and found the payout over time to be identical.
slush's pool solves more blocks per day, but splits the payout over a much larger number of users. We solve less blocks per day, but split the payout over far less users, which equals out over time.
Likewise, slush's pool charges a fixed donation rate of 2%, whereas we charge 0%. So, when observing the estimated earnings on slush's pool, you need to take the 2% donation into consideration.
I recommend watching for a few weeks on either pool and then determining, based on an average of the actual payouts, and not estimated earnings, whether or not the payouts are equal.
But, with different scoring mechanisms you're kind of trying to compare apples to oranges. They're both fruit, but intrinsically different.