Thats a shame that tbh...I am looking at the 620W aswell as i have tested 2 and they were BY FAR the best mid-high end PSUs i have seen.
Your RMA procedure is the big drawback im afraid to say.
Between OCZ and Corsair, if you were interested in helping the UK market, would be the first choice, im sure, for most enthusiasts.
(BTW...OCZ's are the best for DFI boards )