Minor party leaders said neither man emerged as a clear winner in last night's debate.
United Future Leader Peter Dunne said it was unlikely to have swayed any voters either way.
"I don't think you can draw too much from it. They were each shouting each other down." He said Mr Cunliffe, in his first major test, didn't mess anything up.
"But he didn't shut up, and that distracted from the whole spectacle. You can be assertive in a debate without being obnoxious, and Cunliffe strayed close to breaching that."
New Zealand First leader Winston Peters said the only headway Mr Key made was lumping the Green's policies in with Labour's.
"That was not deflected the way it should have been ... But I don't think either side will be happy with the performance."
He said the debate focused too much on the present and not the future economy.
"I thought the critical part of the debate, which is where we are heading in 2015/16/17, was clearly missed.
He said the moderator Mike Hosking gave a "very polished and neutral performance".Conservative leader Colin Craig said that Mr Cunliffe won but only "by a nose".
"John Key was way too evasive and elusive, he was just trying to brush things off. He was very dismissive of land sales [to foreigners], saying it was not a big deal, but how would he know? We don't even have a register to know what the actual number of land sales are."
He said Mr Cunliffe "did alright".
"He was quoting plenty of facts and figures. I think he'll be happy. They were both pretty vague on immigration. They weren't prepared to be clear. We think it should be halved."
Act Leader Jamie Whyte said neither leader ever argued on principles but just quibbled about facts and figures, about what the government had and had not achieved.
"Both men think taxpayers' money should be spent on housing. Even on capital gains taxes, John Key's answer was the government already has a capital gains tax.
"Both claimed that a government they lead can increase spending and balance the books. It seems ACT is now the only party that believes in free enterprise capitalism."