I am also 6', level 8 and weigh a bit more - 220lbs. This past winter I demoed 184 Matra's for a week at Whistler in the Pacific northwest. The skis , as others have described, had good edge hold on soft to medium firm groomers and stable at speed while making GS turns. On hard pack the edge hold was only moderate and the tips wandered at speed. The float in powder (medium weigth - not fluffy) was very good but not outstanding. Comfortable in loose / medium spaced trees, good on soft bumps and excellent in chowder/crud. This spring I bought a pair of 183 Goats. I did not have a chance to ski them in powder but in spring snow they rocked = excellent float and stable through heavy mashed potatoes. Definately felt softer then the Mantras and when I did find some ice under the spring mush, the edge hold wasn't as good. I expect they would be not as quick in trees, but I agree with other posters, more versatile then the Mantras.
Another ski you should stongly consider (probably needs to be ordered in the US) is the Icelantic Shaman (160-110-130) I bought a pair of 173's and skied them in Western powder, TIGHT trees, soft bumps, chowder and soft/medium firm groomers. QUICK turning in trees, phenominal float in powder = effortless, good in soft bumps if not cut with steep faces and stable at speed on soft groomers. This is NOT an ice ski but for the condtions you described, would be an excellent choice. I would recommend 173 as the correct length.
Hope this is helpful - Falcon_O aka Charlie