Just for the fun of it I set up 4 block erupters on Dec 14, all are operating at the same speed, one on each of the following pools. One of those pools is CEX/GHash. Here is where they are at today:

As of 2013231045 (Eastern US)

BTC Guild: 0.00154781
Eligius: 0.00140232
EclipseMC: 0.00141193
Ghash.IO: 0.0015161 (0.02307720 GHS * 0.0657)

The difference between the pools is small, likely due to luck variance only. I purposefully haven't played the market with cex.io and am attempting to make this as vanilla as possible. Reinvesting proceeds with the buy now function only.