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..
so you "say" its stealing 20% profit.. and still it outperforming nicehashminer must be doing something right...
you cant compare a marketplace with a pool
what you can compare:
mine coin X on zpool and another pool with same hashrates, dont exchange to anything.
zpool payout coin amount for a given timeframe will be ~20% less than from other pool
That's not a valid comparison either. Luck can easily cause a large variance, even between different blocks
in the same pool.
You just need to follow a block until it is credited to your balance, verify the credited share percentage matches
your hash rate, the amount of coin matches the percentage of a block, the BTC value matches the exchange rate, etc,
then magically see your balance is credited 20% less than the last value prior to exchange.
If you get paid in the mined coin it's even clearer as it eliminates any exchange fluctuation.
Those defending zpool should just do their own test. I've done my own tests (not recently) and analyzed the data
from two other users who posted detailed information of their tests. Simply comparing with other pools,
and especially Nicehash which doesn't mine coins directly, means nothing.