I understand that the ABS 900W PSU would provide just as enough power as the x650. But I don't see why you would want to pay for a 900W PSU that can only output 800W. Are you saying that the modular cables makes that ABS 900W worth it even though it's only 800W? So in other words, an 800W modular PSU?
Well if the OP thinks the x650 is worth it's price then I dont' see why the 900W abs wouldn't be comparable. I'm just trying to make it as comparable as it can be. Both modular, abs slightly cheaper, 90% efficiency, and has some extra power to boot. Not sure why it would be a bad thing.