This is a hard one. I don't think a loss to Berdych would be the end of the world. And, Berdych is playing well and with more belief. But, at the same time I don't think Nadal has extended himself much either. He went out early in IW and his first three matches here were basically walkovers.
I also don't think the Raonic match is an indicator of anything. Rafa played a nervous first set, but thereafter pretty much had his way with him. I know the conditions were bad, but Raonic actually showed me very little. He has his serve, but his groundies, unless he's going for an outright winner look pretty weak, to me.
His anticipation is horrible and he doesn't move that well. I don't think it took much out of Rafa at all.
At any rate, Nadal has garnered enough points to stay comfortably ahead, so it's a win-win for me.