Frankly, I don't have an interest to say either way. But, I have run 10 D3s and 3 L3s for two days on Prohashing and then on Nicehash and on ZPool. The ZPool payout was more after the unpaid and pending amounts were considered (total earned). Not only was it more, it was substantially more. I will do a test later with screenshots, etc. But, there's no way that I feel like Z Pool is stealing from me. You have to make sure that you are considering the sum of your earned amounts.
No one is suggesting that it doesn't pay out more than other non-yiimp pools. First off Nicehash is not based on the current price of the coin, but upon the price people are willing to pay for Nicehash rental services so the price can vary significantly from the Exchange prices. The point is the amount of coins that are being stated on Zpool that you are mining compared with the prices they should be exchanged for is always significantly lower than they should be. Take a look at ahashpool.com which is also running Yiimp, but has fixed the bug that I suggested earlier in the thread. There when I go and to the same comparison of coins mined to the amount being added to the unpaid amounts it is significantly closer to the true exchange prices at the time.
These prices will fluctuate as the blocks mature and go to the exchange, but they are always in line with what the prices are showing on the exchange. My previous analysis of the coins I mined on zpool often put the value at or below the lowest value for the entire day for those coins. This was often 10-20% lower than what should have been paid out for them. Some people are fine with this payout because as you mentioned Zpool pays out better than some alternatives, but that doesn't make it transparent or fair given what they claim is their payout.