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.