Some of the plusses for this team:
Offense - this is obvious, but the non-obvious part is good too. The team has not just hit, but has hit everywhere (granted, better at Fenway as you'd expect), and has held up very well against good pitching. This has not been all done against #4 starters. There are issues at 3B - but seriously, if Holt or Travis Shaw is your worst non-catcher hitter, that is not too shabby.
Missing Bats - pitching got a lot better, and ended up with the AL's 4th best strikeout rate. This becomes more important in these short series - rallies being snuffed out by the pitcher. Deep lineups and missing bats has been a very durable formula for a champion.
Bullpen - has been phenomenal in September. We know the party can't last. But even so Ziegler-Uehara-Kimbrel is a solid bridge. Kelly and Pomeranz could both be "2012 Lincecum" sort of 6 out weapons to provide even more depth.
Am I picking Boston? Of course not - I have been a fan too long.