I'll be voting for the local MP who best represents me and my community, last time round it was Nick Clegg as he was the only local candidate who talked about the things that mattered to me. Next time it maybe someone different only time will tell, when will people in this country realise that you can't vote for the party leaders unless you live in the right constituency and that blindly voting labour or conservative regarless of the local candidate is stupid.
Most people presumably look at the party and its policies. As we don't live in the US, it's not a popularity contest between two people.