Just from what Ive seen from the 2
Rode with an new m8 and 1000 a couple weeks ago, and both very nice sleds. We were in about 3ft of fluff. The M8 seemed considerably stronger than last years M8. It handled great in the powder and climbed very well. We liked the way it handled going through the trees and it stayed on top very nice. Comes over on its side with very little effort. No real problems.
The 1000 has amazing power. That thing gets u fast to the mountain and just keeps climbing. The bigger fellas really thought it felt more stable and handled better than the 8. The power was just amazing, grab throttle and hold on. In the snow we were riding, the 1000 is still a 1000. You definitely noticed the weight so it had more trouble staying on top, and trenched like hell starting off. The main problem we had was when u layed it on its right side, intake would suck snow, and there that pig would be. And when she gets stuck, she's stuck.
Over all, both great sleds. Really impressed with the 1000