This article http://www.bigmouthstrikesagain.com/archives/5411 is worth a read on both sides. The below paragraphs say it all for me.
September’s vote isn’t about which political party you prefer. It’s about how we keep the bastards honest. Those bastards might be SNP, or Labour, or Green, or Conservative. It doesn’t matter. We’re being asked to choose a system, not a party.
One of the most dangerous ideas that’s gained currency – and it’s an idea that the No campaign is really pushing – is the idea that a Yes vote is a vote for the SNP. It isn’t. Independence could turn out to be the best thing that ever happened to Labour in Scotland, to the Greens, even to the Conservative party: a reborn Scottish Conservative party, one that has more in common with the long tradition of small-c conservatism than the UK party, could one day have more MPs than Scotland has pandas.