Both are at the top of their profession. Both also have competition from Putz, Hoffman, etc. for the totally subjective title of "best closer".
Yeah, the leagues are different, each closer's situation is different, manager's use of the closers are different, their ages are different, blah, blah, blah. All that matters is the here and now...and right here and now I'm pretty happy the Sox have Papelbon.
I couldn't care f***ing less what Saito does or doesn't do for LA...unless the Sox are playing them at some point.