...Anybody know /used them, what do they perform like on snow and ice ?
Here in Santa's homeland, the old BFG A/Ts were considered dangerous on winter roads, unless studded or heavily siped. The new ones, KO2, are much better, at least for the first year or two. When they get older, the rubber hardens, and as the pattern wears, the blocks will flex less and give less traction on slippery stuff.
I have 3 sets for the cruzah,
KO2 in 265/75R16,
Dedicated winter tyres, Yokohama Geolandar I/T-s (G-073), 265/75R16
Studded winter tyres, Nokian something, 275/70R16
I bought the KO2s before a long trip during the summer of 2016. They were fantastic on the tarmac and on forest roads. Very good water drainage too. When winter came around, about this time of year, I left them on, and was surprised at how good they are on snow. Really no reason to put on anything else except for in icy conditions. On ice, only studs or chains give a good grip, but dedicated studless winter tyres also give a reasonable grip, as long as you take it easy. Proper winter tyres have much finer/denser sipings than the KO2s, and give much better grip on hard slippery surfaces. Airing down also helps, btw.
Studless is normally better at all winter conditions than studded except on ice, if all other factors are equal (age, wear, quality, etc). Only exception is dry tarmac, where studded tyres might be better than studless winter tyres because they have a harder rubber; but that comes into play only if you drive close to the limits of available friction.
So this year, with the the KO2s one year older, I'll just put on the Yokohamas and leave them on until the spring, unless there is a need to put on studded.
I have never lived in England for a whole year, but I expect that the winter conditions there would suggest that the KO2 is an excellent choice. For icy roads, a light chain could be an option to letting the car stand still for that one ? day per year. Chains are also good for muddy tracks, so maybe not to bad to carry a pair.
Re chains, for the 100, Mr.T states that chains should not be used on the front wheels. Looking at the fronts, I think the problem is the upper ball joint. If that's the case, there are different designs of chains that could still be useable, if fitted very tightly, and the speed kept down.