I've already said this to somebody else, but I'll say it again. Explain to me how Roddick can have a winning H2H against Djokovic (and a losing one against the old Agassi in Fed's prime years no less), and a Hewitt that has too many operations to count can take sets off him at the Olympics, and the AO. After all, this is the logic we all use when it comes to determining whether prime Agassi can actually beat prime Fed, or prime Fed can basically dominate prime Djokovic is it not?
Just so you know I am strongly on one side in this Djokovic vs Agassi peak to peak thread or prime vs prime thread. My comparision of them:
Better career and greater player all time now: Agassi
Better career and greater player all time in a few years: almost for sure Djokovic
More naturally talented player who had the greater potential: Agassi
Longer and more consistent prime: Djokovic
Who would win if they met peak to peak or even prime to prime: Toss up, Djokovic on clay probably, Agassi on grass, and all other surfaces quite close.
However to answer your questions:
-Djokovic for some odd reason seemed to hate playing Roddick. If you watch their matches the only one Roddick really just outplayed Djokovic was the Dubai one where he served everyone off the court that event, including Nadal as well. The other matches Djokovic blew with a shockingly high # of unforced errors, he had many more winners in all of the other losses even including all Roddick's service winners, and you wouldnt think Roddick could ever outrally or outsteady Djokovic. Just doesnt like something about Roddick's game but I cant pinpoint what it is. Roddick for no apparent reason though was apparently a bad matchup for Djokovic, while conversely Agassi was a nightmare matchup for Roddick. Roddick would almost rather even play Federer than an old Agassi, lol! If this shows anything maybe it shows who really is the GOAT returner though, since while Roddick didnt serve Djokovic off the court totally except for Dubai, Agassi does handle Roddick's serve like it is nothing more than Djokovic or even Federer, which is a key to the dominance.
Lastly Roddick never played 2011 and beyond Djokovic, and I wouldnt like any version (not even 03/04) of Roddick's chances vs the Djokovic hat he has gotten over the hump of living up to his early 2008 set expecatations and gotten over those mental and fitness issues which were enormous for years even as a perennial top 3 player. People say Djokovic cant keep up his 2011 dominance which is true, but even the Djokovic of this year and of future years is a much tougher out for any less than very top tier champion than the previous one was. We will never know for sure since we never see the best Roddick (or any Roddick) vs the 2011 and beyond Djokvoic, but that is the Djokovic which will probably be referred to as peak and even prime Djokovic.
-Old Hewitt is pretty much owned by Djokovic. Apart from the 1 Australian Open set which means very little in the big picture, all of Hewitt's other sets were on grass. Since I never rated Djokovic that highly on grass even after his Wimbledon title, and definitely feel prime Hewitt > prime Djokovic on that one surface, I am not at all surprised even an old Hewitt wins sets from Djokovic on grass. I also feel Agassi is clearly a better grass courter than Djokovic (and a better one than Hewitt for that matter, so for sure a better one than Djokovic). I will most likely feel that way (of course his playing level on grass could further improve in which case I would reconsider) even if Djokovic wins a 2nd Wimbledon, which while a deserved achievement would probably be due to alot weaker grass competition than Agassi or even Hewitt faced. On hard courts when they play it is pretty easy sailing for Djokovic, losing only that 1 set but he was never in any trouble in that match. Still on the whole Hewitt is no more competitive vs Djokovic, than a mid 30s Agassi was with prime Federer.