I have used Suprnova, Coinotron and Dwarfpool.  For some reason, I get more with Dwarfpool and his proxy solution even with a higher difficulty.  5% higher than February with Coinotron.  10% higher than January with Suprnova.  It may have to do with server proximity.  I am using Dwarfpool's server from Montreal, Canada which even though it pings slower than Suprnova, it beats it.