As you can tell I am a rel fan of the Green Diamond's but they are certainly not for all areas.
They are unique design with carbon crystals embedded in the tire so you have the same grip as you would have with studs but with regular tire performance and not the noise and regular road destructiveness of studs.
They are a bit noiser than some all season's but quieter than others.
All I can tell you is that two winters ago I hit a patch of black ice traveling around 40 mph while getting out of the way of a flock of turkey's on the road and the Nokians on the car just didn't cut it. I got interested in the Greed Diamonds reading threads here bout a year ago and the rest is history.
They will serve you well in eareas where you have a bit of snow and ice but you dont want to leve them on all year ... like most snow tires they will only give you 20K-30K before you need to replace theym.
They are for climates where Saabs are happiest like the frozen Northeast (which is now very unfrozen an dbloody hot). Ted Harris Resource Strategy Henniker, New Hampshire