One thing i've noticed is that Rob has a definite pattern to seasons: first few episodes are mostly comedy, then a bunch of storyline, followed by a real winner (One example is my favorite line in season 2: "Will we ever find out why Roamin, a crime solving rank eleven paladin, had an EXTRA jar of pee?") Then a couple of well mixed, then right at the end he sets it up for a last episode filled with epic win, then in the first couple of the next season he does comedy again.
... Well, something like that anyway.