Thatbags, I take both into account for general elections, if I thought my candidate was useless, I would not vote for them regardless of party. Luckily we have one on the best MP's we have ever had and she supports a party I am happy with, so an easy decision.
When it comes to local elections, I want someone that will represent me at council level, I don't trust those that live elsewhere to do that, regardless of what they say, our village has suffered recently from such counsellors decisions. Party politics come second, with a few exceptions. That decision is also made and waiting to be posted.