Reply #10: after I wrote my post I looked up what the LibDems are proposing exactly...

[harmonicon]

and it does involve individual candidates, as you suggest. It seems that constituencies would likely be larger, so people would be voting for a few MPs at a time, with the seats proportionally alloted. It seems pretty good to me. Watching this election (the first general election I've witnessed since moving to the UK), I realized for the first time really how small constituencies are. There are more seats in the house of commons than there are in the US house, and the population is only about 20% of the US population. People really can personally know their MPs, so keeping a system where the electorate is choosing between individuals seems very important.