In reply to rif:
> My car's been on Hankook all-seasons for the last two years and they've been fine: almost as good as pure winter tyres in snow, no noisier than summer tyres, wearing well, and more confidence when driving on wet roads at this time of year.
Another vote for these. I ran them in North Vancouver from November until summer. Probably similar all-round driving conditions to the north of England (wetter, maybe warmer). I thought they were excellent for all the reasons Rif mentions; extremely good grip in the wet, even on warm days.
I did previously run hefty winter tyres year round. They give a 'plush' feeling ride, but IME felt a bit squirly at high speed and in wind. They were OK for Canada's slow, rubbishy roads, but I wouldn't fancy them much for routine use in the UK. Amazing for proper snow and off road stuff though.
The idea of running winter tyres on drive wheels only does make sense if you want them purely to help you get moving on snow and ice. If you want your car to be more 'sure footed' in turns or on cambered roads, you might miss having good lateral traction at the back/front.
Mark