Planet- I have had two different track machines (Bobcat and now Deere) and they are a 4 season machine and IMO, for what I do, they are definetly worth the money. However, going from what I read in your posts, it sounds like you're trying to talk yourself into a CTL over a skid. Don't buy a CTL just to have one. The work great on slopes, grading, push power, machine balance, and so on... The biggest advantage compared to a skid IMO is working in mud. Like anything else, they will bogg down when you get in the nasty sh!t, but I can work in many more conditions that a wheeled skid cannot.
As far as working in snow, do you mean in dirt or plowing on pavement? Digdeep made some good points, but I have to disagree on the snow plowing aspect. I haven't tried my Deere for plowing, but my Bobcat was horrible! CTL's don't bite down, they float. So if you're trying to push snow where underneath is either icy or packed down after it's been driven on, you can't get traction at all. If you were to plow right after it snowed, and the pavement hadn't been driven on or before anything freezes, you might be O.K. However, I'm sure you know if you plow snow that's not the case most of the time. If you did have a dry/unfrozen surface under the snow, that probably wouldn't be great on track wear either. Along the same lines, CTL's do not do well on frost. Same concept.
Planet- I would recommend that you check into a wheeled skid with aftermarket steel tracks. That might be a better all around machine for your needs, and you could take off the tracks for plowing snow, or whenever you worked on pavement. Just my $.02!