Actually, Hewitt has been a good clay courter and Roddick is not better than him. Nadal is a great clay courter and Roddick is not better than him. Federer is a good clay courter and Roddick is not better than him.
Safin is a good clay courter and Roddick is not better than him. Agassi has been a great clay courter and Roddick is not better than him--maybe now that Andre is 36 and has a bum back, but Agassi has been the better player by far from 2001 to 2005.
Nalbandian is good clay courter and Roddick is not better than him. If you remember, Nalbandian schooled Roddick the same year he won the Open and dusted him the first two sets and had several match points to win in straight sets, but blew a couple of points and then had a huge let down after blowing the second set. Watch how Nalbandian beat Federer in the "fifth" slam in December? Roddick would never do that. And Lubicic has a much better game and is a better player than Roddick. He's clearly proven that in the last few years. He serves almost as well, but has more consistency, better volleys, better backhand, better slice and more.
All of those guys have better all around games than Roddick. They use the whole court better, they have better angles, drop shots, volleys (except Hewitt and Agassi) and are more consistent. Every one of those players at their best is BETTER than Roddick. And Haas has shown to be better than Roddick as well. His poor health is the only reason he has not accomplished more.
There are at least five other players who have a more versatile and well rounded game than Roddick. Roddick's two hand backhand is so far below the greats of the game--Borg, Agassi, Wilander, Connors--even Ferrero, Hewitt, Grosjean, Nalbandian, Lubicic--they all have considerably better backhands. Feel? Roddick doesn't even measure up to today's best players in the feel department, let alone the greats of the game. In his prime, Connors would have had Roddick for lunch. Sampras? He already destroyed Roddick a few times and in his prime, would have beaten him regularly. The ONLY way Roddick competes against any of the world's greats is if he has an incredible serving day and his on with his forehand. His return of serve lacks variety and is inconsistent. But if his serve is on, he can take chances on his return and get a break here and there. That's the only way he can beat the best. If you look at his history, he continually fails to win big matches against the game's very best when they are at their best. He can't beat Federer, he can't beat Hewitt, he can't beat Safin, he can't beat Lubicic, in the past he couldn't beat Agassi--when they were at their best.