Usually between westhash and f2pool - whichever one is higher payout at the moment.
I've written scripts to manage the miners and change pools according to highest payout.
Sometimes I'll swing them at a PPLNS pool if I think it's due to have a good day, but mostly leave it auto to PPS pools.
F2 is PPS and guess your talking about Ant's PPS pool? So ant is 2.5% and F2 is 4% PPS, right? So best you will do is 97.5%? I've tried both and also several PPLNS, mostly on Kano now, since June I have been split with Bitminter and Kano, if you look at the 26 week numbers, I'm avg. 102.5%. Kano is now over 6ph and I see a lot of new miners there, sone at over 500th and 1 new guy at 1.1PH. I think Kano has the best code on the network, fast efficient and 2 orphans EVER. Maybe give it a try? Need to be there for 30 days to really see the effects
F2 is 4% PPS, but you do get a small kickback with NMC and Huntercoin. The other PPS I referred to, Westhash, is western variant of Nicehash. Payout can vary widely depending on rentals and altcoins. I thought about trying Kano, as I had read many good things about it recently. I may send some hash that way for testing.
Hope to see ya there, just remember the 5N so ramp up is about 4 days and ramp down 4 days, you really need to give it 30 days to compare, but many other including myself have run 1,2,3 month compares with other pools and Kano came out on top.