The stats are correct but the return is almost always lower on zpool than on the other pools that doesn't autoexchange.
ex:
skein
zpool.ca 24hour payout per ghash: 0.00449BTC
yiimp.ccminer.org payout per ghash: 0.0062BTC
+38% if you mine on yiimp and exchange your coins yourself.
But zpool is more profitable than the nicehashminer..
Fact i actually test (not speculate)i've test with multiple rigs had 1070x4 on nicehashminer / another 1070x4 and zpool nemosmier /and another 4x1070 on nemosminer Mining Pool Hub
the zpool version is making more every week so i don't believe there is any theft going on my payouts seem to always be correct..
ex:
blake2s
zpool.ca 24hour payout per ghash: 1.17497BTC
yiimp.ccminer.org payout per ghash: 0.41053BTC
+186.2 if you mine on zpool
zpool blake2s and lyra2v2 are 2x the profitability compared to yiimp.ccminer.org....
You have to remember the luck factor, you need to run test cocurrently for them to be comparable.
That said I've not tried Zpool, I'm going to try a week on miningpoolhub and see how it pays before switching