What makes great special teams?

I know all serious special teams coaches grade and evaluate their players but what do you base subjective team grades on? For example, what does it take to call yourself the "best special teams in your league". Is it a great kicker/punter? Is it a team that blocks a lot of kicks? What about a team that has a lot of good returns? Or a team that runs an innovative scheme? Frank Beamer has long had a reputation as having the best ST in college football, but what sets him apart from Miami, FSU or Air Force? I guess this is a subjective judgement call and the obvious answer is all of the above, but what about a team that gets a lot of blocks but no returns? Or a team that has a great punter but a lousy kicker?