The cards he's using should make no difference to you whatsoever (even though he IS using 6990s). 1 Ghash = 1Ghash whether or not it came from 1.5 6990s worth of flops or a hundred 1900XTs..

At current exchange rates, it looks like Vladimir might have some serious competition in the newly emergent mercenary miner market!

Nakowa is more than $100/mo. cheaper!