On the MTF debate I just want to mention that outdoors, Fed has always played Nadal on slow hardcourts, i.e. Miami (and first time he was ill) and the Australian Open, plus only once in Dubai.
When Fed won against him comparing to when Nadal won is generally summarized by "outdoors/indoors"
but nobody knows if the distinction is not rather "quick outdoors / slow outdoors".
Fed and Nadal never played against each other in the US Open, Cinci, Toronto/Montreal, Shanghai.
The Fed-Nadal H2H is like that : hugely biased in surfaces, yet will always be remembered as it finally happened to be.
Was a benediction of God for Nadal : both great match-up and surfaces exactly made for him.
If Fed had not been there, Nadal would have been much lowly considered.
That said, Fed might have won one of these finals now, might have, and I'm one who can never imagine Fed beating Nadal before they play, including before their WTF match
Agree with this, Despite huge match-up advantage for Nadal, Federer will always be favorit indoors and on faster outdoor HC, but like you mentioned thay never played during summer fast outdoor HC, i would love to see Roger destroy Rafa in Cincinnati
About their outdoor HC matches. Roger won only 1 5setter at Miami, when he was playing at his peak and Rafa was still not such great HC player like today, also that los in Dubai - Roger won more points in that match than Rafa. Other matches like 2xAO, were close but Rafa won those matches, Roger wasn´t able to penetrate his deffense on such slow surfaces.
Interresting thing is also that both Roger´s victories over Rafa on clay came on clay courts that suits his game.
Madrid is known as probably fastest clay event and Hamburg was Roger´s event, he was there very good, low bounce for clay and Roger was very succesfull at Hamburg´s clay.
Generally we can say that faster the surface better for Roger and opposite, slower the surfaces Rafa takes the edge.