I don't agree much with Michael White, political editor of the Guardian, says, but he is spot on on this one
"Why we should cherish prime minister's questions
Rowdy and undignified, it's the bear pit of British politics. But in the age of 24/7 TV news, instant blogging and Twitter, a strong performance at PMQs has never been more vital"
....
Apart from entertaining the sketchwriters, does the weekly session of political mud-wrestling matter? As with John Major, Tony Blair and Gordon Brown before him, Cameron has deplored its rowdy, Punch-and-Judy qualities . They all look back nostalgically to a golden age of scholarly exchanges between gents and promise to do better, at least in the early stages of their rule. Cameron is only the latest prime minister to acknowledge defeat.
Does it matter? Of course it matters."
...
"cerebral Arthur Balfour could complain that answering questions on "trifling subjects" wasted "the best hour of the day". Worse, it was undignified, stirred up friction and personal abuse – complaints still heard in 2011.
Typical of an intellectual, Balfour missed the point which Thatcher would forcefully articulate in her memoirs. PMQs were "the real test of your authority in the House, your standing with your party, your grip of policy and of the facts to justify it," she wrote. Few heads of government are so accountable, as she liked to point out at EU summits. Few fellow-summiteers "know where their parliaments are," she once snapped.
In her day the ordeal was twice-weekly, at the fixed time of 3.15 pm on Tuesdays and Thursdays for 15 minutes"
...
in his final speech there Blair admitted he had "always feared" it."
www.theguardian.com/politics/2011/jun/18/prime-ministers-questions-ed-miliband-david-cameron
It is a real test for them and they fear it, but it keeps them on their toes and lets the public see what is behind their mask.
Of course, they want to change it and make it polite and gag Pickles. But the people want to see democracy in action, and Thatcher would not hear of changing it for one second.