I'm not sure I agree, mikey, that the lack of substance was their downfall. Or at least, it shouldn't have been. Of course there could be no answers about what Independence would bring. In the first place there had to be negotiations, the outcome of which was hardly going to be that everyone rolled over and gave Salmond and Scotland everything he and they wanted. And in the second place, it wouldn't have guaranteed any policy direction anyway, because of course this was a vote for an Independent Parliament rather than for an SNP Parliament.
The mistake was, or seemed to me to be that, Salmond and Sturgeon and others would grudgingly concede at least the last point, "This isn't a vote for the SNP, this is a vote for Scotland", but then wouldn't shut up about all the policies they planned to introduce, and about how awful Westminster was currently, and how everyone who disagreed with their policy direction claims were ignorant/ stupid/ scaremongering. They couldn't make promises about policy, in other words, but couldn't seem to shut up about that aspect of the debate. In the long run this was always likely to scupper their claim.
It should, really, have been a debate with far less substance and far more about ideology. The question after all on the ballot paper was "Should Scotland be an Independent Country?", rather than "Should Scotland remain in the EU/ Nato/ Sterling. but switch to a generally more left-wing course?" The attack on Conservative politics, for example, probably ended up losing a majority of the 17% or so of Scottish Conservative voters, who might have felt more of an appeal if Independence was sold as a chance to make even their voices louder, rather than just the voices of the left.
I still think they'd have lost that argument, of course, but on policy the Yes campaign was bound to lose because they could, almost by definition, have no answers. No wonder Salmond and Sturgeon were so rude and dismissive about all the legitimate questions raised. They had to be, to try to deflect attention from their own empty position.