You do see the irony of using a first-past-the-post vote to canvas opinion on this subject, right?! Faults with both systems - PR can give disproportionate influence to fringe parties, which is easily exploited. (Saying that, the Ulster Unionists exploited the small Tory majority in the early nineties to dictate Northern Ireland policy so there's no guarantee first-past-the-post prevents similar abuse.) In a three party system a single party can (theoretically) receive only marginally more than a third of the vote and still win every single seat in the commons under first-past-the-post. No doubt about it, we need some electoral reform although I'd start with a genuine opposition party as opposed to the lesser of two evils we have today...
Prefer the way the French do it - an initial vote and then you knock out the bottom parties and you end up with the 2 contenders against each other