I've been flip-flopping between EMC, BTCGuild, p2pool, and slush's. My payouts have been basically the same across all the pools, though the speed of payments differs. With a slow pool like p2pool, I was getting the same payout, but it may take a few days before the payments arrived. BTCGuild, with it's fast blocks, means no waiting for payments. EMC is fine, no problems with it to report.
I'm currently mining with Slush, out of loyalty - I started out mining there back at the start of the year with a lowly HD5870. I was getting more BTC back then with that single 5870 than I am now with 2x ASICMiner Blades, 11 ASICMiner Erupters. Of course it's an addiction, so I've two BitFury USBs on order, waiting on a Jalapeno since July, and am bidding on another Jalapeno April pre-order. I know they won't make back their value now, but I'm stock piling BTC for when they shoot up to $275 again....
i hear ya , thats a lot of hashing power you got , i dont think people realise that once bit coin goes mainstream you will be looking at a single bit coin being worth around £1000 each
