RM is where he is going, of that I have no doubts and he will be fantastic there. That too I have no doubts about, but for me he is still learning his trade. He has the raw talent to be as good as say Ronaldo, I believe, but he still can't produce it on a regular enough basis yet to be put in the same bracket as Messi and Ronaldo. His relative inexperience sometimes leads to him over elaborating or shooting when he should not in my opinion.
Ronaldo is actually good comparison in that he started off at Utd doing stepovers and the like for the sake of it, but by the time he joined RM his every move had a singular purpose to it. He was using those skills at the right time to deceive the defender and skin him. He learned or was coached into doing the right thing at the right time, and this is where I see Bale falling down. If he goes to RM and has one good game in three or four he will be slaughtered by an unforgiving crowd. One more year at Spurs and he'll still get his move to the Bernabeu and be a more rounded player as a result.
That's what I think anyway.