In reply to alasdair19: I was based in Cham for the last 4 winters, skied a lot of days on GM in all conditions.
I've got Volkl Mantras, very old and wrecked Gotamas and some 4frnt EHPs. Had a shot of a mate's Blizzard Cochise 193cm for a few runs last year - I thought they might be too much ski but they we phenomenal. If you can find them, buy them. Any price. Just buy them. Stop reading now...
Ok, some quick opinions:
Whitedots - never skied them but no-one I know rates them. Too much sidecut usually and shovels too big.
Black Crows - mainly skied by people sponsored by them, but no personal experience. Meh.
Dynastar - still haven't bettered the legend pro rider. Don't know anyone who's skied the 105. I've never skied them.
K2s - I've had Hardsides, friends have had sidestash. Fine skies, not very exciting but dependable and often cheap.
Atomic Automatic - as HeMa says, another dependable choice.