There are plenty of reasons to take issue with the substance of Ed Miliband's speech this afternoon.
He banged on yet again about the cut in the 50p tax rate, which strikes me as dangerous now that it seems clear he is unlikely to promise to reverse it in office.
He did virtually nothing to repair Labour's tattered reputation on managing the public finances.
He claimed the 'one nation' mantle whilst fighting the class war with greater venom. And he attacked the Government as "useless" and a "miserable shower" which runs the risk of making the party look complacent at a time when we haven't entirely forgiven it for its own mistakes.
But it was a damned good speech all the same.
Ed's problem when he walked into that hall was that even some of his own supporters could not envisage him as a future Prime Minister. That isn't going to change in one afternoon.
But today's speech was, on any measure, a giant leap forward. He was relaxed, confident, authoritative and witty. He totally dominated the hall.
If I'm honest, it is probably the first time I have ever really been able to envisage him actually standing on the steps of Number Ten. He rather reminded me of Tony Blair. And I mean that as a compliment.
If the Tories aren't worried, they should be.