Out of curiosity, I've just run a 48 hour back to back comparison of Hashcows and pool mining CGB. My miner is 2 x7950s and 1 x 5750 which puts out about 1460Kh/s. I ran it on Hashcows for 24 hours and then switched to the CGB pool for 24 hours.
After 24 hours on Hashcows I earned 0.02843 BTC (I had to wait till the most recent payout a couple of hours ago to get the final balance). After 24 hours on the CGB pool I earned 0.02776 BTC. However, the kicker is if I adjust my CGB earned to the price it was when I stopped mining on Hashcows (to make the comparison fair), I would have earned 0.02840 BTC...
The bottom line is a 0.00003 BTC difference!! One might say it's not worth the effort, but, I'm getting the Hashcow payout in BTC but with mining CGB I have to move it from the pool to Cryptsy, sell it for BTC and then move it to my wallet, 3 lots of transaction fees/commissions compared to 1. When you consider that Hashcow charges 2.5% compared to my CGB pools 1.5%, I think they are on to something here.
However they would really be on to something if they trim that 2.5% to say 2%. That would make a tangible difference! Just a wink,wink, nudge,nudge suggestion..