I haven't seen it yet, but despite whatever allegiances Hislop might have, I tend to find he rails against all parties equally; accusing the Lib Dems of being pointless and... uh, never likely to gain power... the Tories of being slimy and elitist and Labour of being incompetent and tired. HOWEVER, I do find he goes on a bit too long whoever he's bitching about. He tends to make a clever, slightly subtle and ironic statement, which I laugh at, but then continues with it long after it's stopped being funny or informative. He just ends up looking very self serving and pompous.
And yeah, Paul Merton's spark seems to have gone lately. Maybe he turned the telly on and saw one of those awful Direct Line adverts? He doesn't get much of a look in anymore, which is a shame because he is still really funny when he speaks.