Goldfine would be good for an player just rising from the junior ranks. He can teach technique and positioning and so on. Roddick's basic game isn't going to change all that much. He needs someone who can work on his head.
Roddick was tremendously confident coming out to play. He was confident in the beginning but he makes a few mistakes, Lux hits some shots and then you can see his confidence go away even though he was simpoly tied in the 1st set after Lux broke back. Then Lux started playing really well and ANdy started playing more passively, not hitting big FH's whne he had the chance, hitting short shots off of both the FH and BH wings and then Muller ripped some amazing shots.
To Muller's credit, he didn't crack under pressure. 99% of Roddick's oponents crack under the pressure because he his holding serve so easily. His opponents hold serve well against him but then there is always that game that has a Df, an eror, a good Fh by Roddick and then the pressure builds because it is so hard to break Roddick. Muller totally kept his cool and kept hitting big shot after big shot after big volley.