That wasn't aggressive or nasty Bobby, please be a little less sensitive.
Nadal was easily playing some prime tennis in 05 and 06 especially on clay.
But let's discuss those years in a little more depth. I hope you won't just gloss over this. Let's also have a look at some of Rosewall's draws - perhaps also confining it to his best years. Considering you pick 3 of Federer's I will look at 3 of Rosewall's namely 61, 62 and 63. I trust you have no objections.
Of the years you mention only 06 could be considered weak, in 2004 these are the players he beat in his slam runs;
AO - Hewitt, Nalbandian, Ferrero and Safin (albeit a very tired Safin)
Wim - Karlovic, Hewitt, Grosjean and Roddick
USO - Agassi, Henman and Hewitt
Now that is a very solid and strong list of opponents. Most of those guys were playing really good tennis that tournament and in the tune ups. On grass you had Roddick and Hewitt as competition playing their peak tennis. Hard courts there was Roddick, Hewitt, Agassi, Nalbandian and Safin. On clay you had Moya, Nalbandian, Coria, Gaudio. Plus you had players like Fernando Gonzales, Ljubicic, Joachim Johansson starting to come through. It was a strong year with 7 slam winners in the top 10.
In 2005 he was stopped at the AO by an on fire Safin in one of the great matches of all time. At the French Open Nadal beat Federer in the semi's in a competitive 4 setter. Both strong competition.
Wim - Ferrero, Gonzales, Hewitt and Roddick
USO - Nalbandian, Hewitt and Agassi
Nadal had his break out year and played some great tennis on the clay and also on hardcourts pushing Federer in Miami and winning Montreal and Madrid Indoors. So he was still very strong. Even 19 year old Nadal would certainly be #3 in this era.
2006 was weaker as Roddick (till the end of the year), Hewitt and Safin fell off. But Nadal was still strong on clay and played a good Wimbledon. Good but not great players filled the gap. Even still every great champion often has some weaker draws and wins. I don't think 2006 is enough to devalue the years before it.
AO - Haas, Davydenko, Baghdatis
Wim - Gasquet, Berdych (both young but still talented and tough for 1st and second rounds) and Nadal
USO - Blake, Davydenko and Roddick
So weaker for sure but Roddick and Blake at the USO were playing very well. Nadal was also quite good in 2006 though not at 07/08 levels of course.
In the early 60's the pro tour was much weaker than it had been previously, Gonzales was semi retired and over 30, Hoad was injured and in Rosewall's best year Laver was a rookie and far from his highest level.
In 1961 at Wembley, Rosewall had to deal with 40 year old Segura (and you call Agassi in 2004/2005 old!), Olmeda and Cooper (both best of 3) before the finals. Now I'm sorry but that's not exactly a tough draw. None of those won more than 4 games in a set against Rosewall, though he was in great form. In the final he of course played Hoad. Immediately that's not a draw that screams tough era to me. A slightly worn out (and injured - back problems) Hoad is still a good finals opponent though.
Rosewall skipped the US pro, at the French Pro he went through Haillet (who I confess I know little about, I must assume he was not particularly noteworthy - Sorry Haillet), Cooper and Segura. Again not a particularly tough draw to the finals on paper but Cooper pushed Rosewall really hard. In the final he met Gonzales, so a good final opponent. So that looks like a better win to me.
Onto 1962, Wembley he went through Anderson, Cooper, Segura and Hoad. The last 3 of those actually pushed Rosewall very hard. So that's a very good win for him I think. Feel free to correct me
The French Pro, Molinari, Buchholz, Cooper and Gimeno. A solid group of players for sure though it's my personal opinion that this group is certainly no better than many of the players Federer went through in his slam runs in 04/05. Plus it was only 4 rounds as opposed to 7.
In 1963, Rosewall swept the pro majors although I don't give it quite as much significance as you do considering Federer won 3 majors in a year 3 times. Connors, Wilanda, Nadal and Djokovic have also won 3 slams in a year.
At Wembley he only had to win 3 matches and only 2 best of 5 set matches. Trabert and Olmedo were his first 2 opponents. Then he faced Hoad for the third time in 3 years. I don't rate this one tbh. Yes he faced Hoad but he only played 3 matches. Hoad was also tired from his semi with Buchholz an epic 5 setter. This is only better than Federer's 2006 AO IMO.
At the USO pro Rosewall went through just 3 rounds, beating Trabert, Olmedo and Laver (who was clearly a rookie at this point). I don't think beating up on rookie Laver is so impressive. Likewise I'm sure you'd devalue Federer beating Nadal in 2006 at Wimbledon. But Federer at least played 7 rounds.
The French Pro was again only 3 matches for Rosewall, but he faced Hoad and Laver back to back. Laver showed how much he had improved and had chances to win the match but Rosewall was too strong in the fifth. Good win for the final 2 opponents but only 3 rounds.
I really don't see how Rosewall's 'peak years' were any better than Federer's. He played mostly the same opponents every pro major and these guys aren't exactly all-time greats and if they were they were getting into advanced years. There were of course some great wins but I think Federer's 04/05 draws hold up very well, especially considering all of those were 7 rounds best of 5 (with the occasional walkover).
I hope my effort to discuss the details of their draws and victories isn't wasted on your Bobby, please don't just post a few lines with broad disagreements.