i think i've figured out why this show has dropped off a cliff (for me, anyway): it used to be a show about smart people being buffeted and worn down by the ridiculous, cynical, PR-centred and inherently hypocritical world in which they operate (much like TTOI). the characters are highly capable and highly successful people, and behaved accordingly. the wordplay and humour was correspondingly smart.
this season, it's about a bunch of really stupid characters falling into basic sitcom tropes and situations, and dealing with them in really stupid ways. the dialogue is dumbed down considerably - lots of standard stuff about bodily functions, and lines with nothing other than shock-value - and i don't think i laughed out loud once in the last episode. the acting talent is still solid gold, of course, and that's just about enough to carry it across the line, but the season has been a real disappointment so far.