It's been ages but I remember watching an episode of Whose Line... and thinking he was fairly shit. My sister (not the one I fancy) agreed, so it must be true. He also did the voice for Wiggy or some such shit, the weakest character in Jasper Carrot's weakest series, so I've never been a fan. But Hercules knows shitloads more than me about vintage comedy, so...
I think John Lydon's lyrics are useless. But I could be wrong.
PS I f**king hated John Sessions in Whose Line. Acted like he owned the f**king place. On a positive note, he was in Happy Families, the lost gem.