If you are a small miner, where can you go today to mine? And I don't mean to mine at a profit, but to minmize your losses and come anywhere near breaking even! Just like every small miner, I tried a lot of the different pools - Slush, BTC Guild and GHash.io, just to name a few. I was very happy to mine at Slush's pool, because I could make more that at the bigger mining pools. I was making twice as much with Slush then with GHash.io and BTC Guild, but then a few weeks ago, the perfect storm hit Slush - the difficulty increased and the hashing power more than doubled - it went from 2Ph/s to over 5Ph/s. Slush went from finding 8-10 blocks a day to only 3-4 and the payout was cut in half because of the increase of hashing power. Maybe some of the large miners pointed away from GHash.io to Slush and other pools to reduce GHash's 51% several weeks ago.
For all these reasons, I am shutting down my 10 S-1 Antminers and putting them on Ebay.
Rock53 -- please take the time to do a bit more research. Much of what you said may be your experience but is not based on sound understanding of mining.
The perfect storm you mentioned, difficulty increased and hashing power more than doubled isn't a perfect storm.... Difficulty increased happened *because* hashing power increased. The two are not independent of each other. The only thing you should pay attention to is difficulty increasing. It represents the bitcoin protocol trying to adjust so that blocks don't get solved more often than about every 10 minutes, no matter how much hashing power there is.
If Slush's made you twice as much as GHash or BTC Guild, then you were simply getting lucky for a short period of time. If you waited a bit more with Slush's you'd see it all equalize. The only reason to choose one pool over the other is their reporting tools and their consistency in paying out. Other than that, you will see the exact same payout over time (perhaps more for a day or two then less for a day or two). The smaller the pool, the greater the variance and length of high days vs. low days. But over time, they will all be the same.
As to you selling S1's .... great idea... their value is approaching 0 due to their electric inefficiency so good time to bail.