AWD is another way manufacturers are up-selling and trying to get more profit out of us. If you're driving on the roads in the UK I really don't see the need for it. You also get more drivetrain losses in efficiency so not only does it cost more upfront, it costs a little more to run. How much more depends on the car though.
I can understand AWD for performance cars, e.g. GTR or rally-inspired vehicles, but unless you live down a mud track or on a farm I don't get it. Especially since we have weather where it would *maybe* help perhaps once every two years for a day or two. If you're worried about winter traction, a spare set (4) of wheels with winter tyres fitted will be way more effective as others have said. If you don't trust that, here's a practical test:
My experience of driving RWD in the snow (Lotus Elise) was actually that it is quite controllable and predictable if you check your speed. Perhaps that's partly the car as well, I've seen Mercedes E-class etc. really struggle but I think some of that was auto box plus inexperience..
I found FWD cars actually more challenging to corner and were very prone to understeer which isn't fun when you're braking and steering.