To me Fed will always be the better player because I personally enjoy watching him much more. I don't believe the Nadal of today would have beaten the Fed of 2004. But Fed is 4 years older now ... while Nadal is still only 22.
nadal is better at playing the safer percentage spin game with his 98+ inch head, and clearly the better player on clay where his wheels do the talking
oh, and also better at disrespecting the game by using convenient gamesmanship of rules (which he is allowed to get away with cause mr disney and his henchman dont have the balls to call him out on it consistently) to stall and disrupt psychologically the opponent.
from a creativity perspective, nadal is second rate to federer, who is a magician at wielding a much tougher racquet on a much more difficult timing-based-game
Santoro's creativity trumps them both
federer's game transcends era, much like an agassi or pancho gonzalez
nadal's game with lower racquet technology would make him a solid topspinner in the 80's, much more exploitable due to spin not landing as deep as in current era.
Nadal is better ***THIS YEAR*** no doubt on that. But you should have no doubts on who has the best tennis skills.
Nadal is this good because not only he is an *awesome* tennis player, but he also has an incredible physical form and mental strenght. In the two last parts he is definitely stronger than Roger, even tho Roger is always well prepared fisically too.
Nadal's strength is better than Federer in 2 areas: fitness and mental strength. Right now Federer's mental strength is lacking. If he acquires that back, Nadal will not beat him the way he has this year. I still think that by the time Nadal is 25, he will not be as effective as he is now. Without his wheels, he would be a top five player. Just my 2 cents.
If we are talking about 2008, then Nadal is the better player. I still don't think Nadal's career will be as great as any of the top five players of all time. He will definitely have an Andre Agassi career.
What a lot of idiots here need to realise is that Federer is past his peak and he is still fairly dominating (2 slam finals, 1 slam semi final... 2 master series finals), Nadal would have been absolutely crushed by Federer at 23 or 22.