It's apparently on STV's version of iPlayer now, although that went tits up at the time as all the people in the rest of the UK who were interested all tried to use it.
The general press consensus both sides of Hadrian's wall seems to be that while Darling was no great shakes, Salmond made a bit of a hash of it. However polling shows very little variation from before the debate and what data there is shows it didn't so much change anyone's mind as harden the views of people who had already made their mind up.
As things currently stand, polls show a 10% majority against the separation. If that's the result, independence in Scotland is done for a couple of generations and Salmond is done as a politician.