Corbyn has just asked his six questions at PMQs and he was not a complete disaster area.
Like all newbies he started by saying let's have a new more adult PMQs with serious questions and serious answers. They all do that, and it generally lasts all of five minutes before they degenerate into slagging each other off.
But Corbyn has found a tricksy style which Cameron will find difficult to crack. Corbyn announced he would be asking questions sent in by members of the pubic - so immediately the PM is on the back foot, he cannot diss the public. Corby said he has received 40,000 questions and proceeded to read a few out, giving the first name of the questioner each time. The PM dully answered, after which Corbyn gravely told him why he was wrong and then moved on to the next question, thus allowing him the last word on each subject.
The usual PM tactic to deal with the 'last word' problem is to bottle it all up until he answers the leader of the opposition's last question and then give him both barrels secure in the knowledge that he can't shoot back. However, with a named member of the public asking the questions, and the real prospect that the Labour Party might actually produce this member of the public tearfully lamenting the PM's rudeness, Cameron cannot afford to let loose and has to just answer on the facts. Hint to Corbyn for the future: make sure the last question always comes from a woman, the tearful lamenting will look so much better. So "Dave" is on a sticky wicket here. It's not clear how he will take Corbyn down. Some pondering required.
After Corby was done, the leader of the SNP in the House (Alex someone-or-other) asked a few questions and the PM wiped the floor with him.