Roddick +7 slams.
The mental slump that Roddick fell into is equivalent to the mental slump that Murray has just gotten out of. The constant losing to Federer and not winning any more slams REALLY got to Roddick.
Victories build confidence which and also create imposing figure for others to beat and builds knowledge & experience of how to win.
Roddick would have maintained his confidence in order to continue pre2005 attacking form and not the post 2005 pushing form. He'd probably have 7+ at least (3+ of which are Wimbledon). And discussion whether he's just below Agassi in best list (even though hes not).