I watched it this morning on iPlayer. None of them conducted themselves very well in my opinion, including Nick Griffin.
I did expect him to be able to espouse his opinons better, because when you have extreme/different (delete as appropriate) views you had better be good at the rhetoric/background/facts/getting the message home. He was no Adolph Hitler
, Mosely or Enoch Powell, (insert name of leader/politician with extremist viewpoint here) then again they never had to go on Question Time (well maybe Powell did, no idea)
He is obviously a rallying point, which is of course an important issue.