Yep, heard that myself.
From experience driving on mountain roads abroad in winter they make all the difference as you can drive much the same with snow on the ground as you can here in summer with the summer tyres that you get on most cars here
I think i'm going to get some Bridgestone A001 tyres. They're all season tyres rather than winter tyres and rated to 149mph - which is something you'll struggle to find with pure winter tyres, so i'm not expecting any problems with my insurer. They'll be easy to live with when the compacted snow and ice isn't on the roads too, but will grip nicely when there is
I'll change them over next spring when the warm weather kicks in then keep changing them over until I need to replace them with a new set.