Skids are great removing snow , but without tracks on them you can get them stuck easy if the ground isn't level. In parking lots there hard to beat . If your looking into one tracks might be the way to go, but I still think about ground clearance under them. I find that I can get closer to things with the bucket ,because you can see the edge of your bucket better. You can lift alot with them and bust though hard pack snow banks pretty easy.
Tractors, can work in most all types of situations. You can get a wheel off into the snow and get out ( most of the time). Skid steer without tracks would most likely, if on uneven ground spin itself right into getting more stuck.
Tractor you can dump the snow further away from the drive-way because of the reach.With a tractor you can have the option of having a rear blade or a snowblower and still have use of your bucket.
One other thing, spin around on concrete or a tarred driveway with a skid steer with tires and you could see black marks. I still think as much as I like skid steers and they are powerful machines ,I'd still go with a tractor.
If you do get into a pickle getting stuck ,you can always use your bucket to lift and roll back right? But if you don't get the snow scraped all the way down to the ground and ride up over it where your wheels break though your only going to be trying to push snow with the back of a skid where with a tractor you don't run into that problem. Just a few things I've run into using both.