Underneath it all, though, there was a substantive clash between the two sides. In a spritely performance, Harman wisely avoided an "investments vs cuts" style attack, instead charging the coalition with not having a mandate for many of its political reforms. Whereas Cameron accused Labour of not facing up to its fiscal legacy. Or, as he put it, "The only golden rule is: never trust Labour with our economy."
Taking questions, Cameron was nimble and forthright. David Blunkett's attack over the Child Trust Fund was countered with a splash of acid: "You break the nation so badly, it's schemes like these that can't be continued." And Denis Macshane's innuendo about the Tories' European allies was slapped down with some choice quotes from some of Labour's own dodgy partners. This was a Prime Minister very much on the front foot.
One final thing to note was Cameron's emphasis on Iran. Like Liam Fox at the weekend, he spoke vigorously against the country's nuclear programme, arguing that "stronger UN and EU sanctions" are required. Worth keeping an eye on, this: it is fast becoming of the major themes of the coalition's foreign policy.