For Nole to lose to Roddick is a real set back. Of course he struggled beating the lesser players in the earlier rounds, but he usually makes Roddick look like a senior player.
I think if he stays with Head, he will probably drop out of the top 10. Forehand less effective, no confidence on serve, overall he has dropped a level since switching. But I guess the money was good, I still remember what Head did to Juan Carlos Ferrero, he finally gave up and went back to Prince.