Rest vs rust has always been a fun debate, but all the arguments are made post hoc (monday morning QBing). The 07 Sox were the best team in baseball - and while the best team in baseball winning the WS is not that frequent an event, worked out then. Colorado being iced for 9 days is one thing, but you don't want them to not win games either. Nature of these things (and the 2 best teams in the league were playing in the other semifinal anyway).
It was 5-innings, but also 5-innings for your #5 starter in a NL park. Basically Tito lifted him after a 2-out walk to get to Delcarmen. At that point, 92 pitches, left with a good outing and backed up by an excellent bullpen.
The winning too early thing has some good recent examples behind it - but it is very hard to see it as a real hard factor. After all, in 2007 the Rockies had to wait, but in 2008 the Phillies had to wait for the Rays to survive Boston - and it did not seem to impact things too much.
Looking at the examples in the last 15 years or so - it seems like when a team sweeps and a team goes the distance, there might be a rust factor - maybe. But otherwise it's pretty much a non-factor. Baseball is just a funny game too - after all, a 7 game series is barely a ripply in a regular season. In the context of baseball, it might as well be single elimination.