Best pool right now on hasflare? F2pool, what is that?

[Agraoleom]

Today my mining on Hasflare has gone down to 6691 satoshi/Ths, which is absolutely horrible, and it has been a downtrend for a while

I can choose BW, Slush, and Antpool. I have had about 40% Antpool and the rest 30 each. Now I want to change, what is best right now?

Another thing I am wondering about is, how is it that many people seem to be able to use F2Pool? I have never had that option. And I have never seen anyone use BW. Is it only me who have that optiont?