The problems with PR is that you would have to accept that your local MP may not represent the majority of voters in that constituency. Ie perfectly possible to have a 80% labour voting area to end up with a Lib Dem MP. And that won't go down too well with voters as MP's are meant to represent your area, not just who you want as a Government otherwise you would just have the choice of parties on your ballot papers.
We would still have had a hung parliament:
Conservative: 235 seats
Labour: 190 seats
Lib Dem: 150 seats
But equally people would have to accept the BNP would have 13 seats.
That may not rest too well with some people.