pretty sure they keep the tx fees  and take 1.5%

how big are you ?

100th

1ph

10ph

I think slush pool is a bad choice  if you go off line  you can lose  a blocks earnings it they hit a block.

I have about 570th pointed to viabtc..  they pay 99.49% with zero variance.  sometimes they drift  up to 103.25%  if tx fees are high  they feed  some of them back to you.

they have zero variance.

I get about 0.02 btc from them every day.