Tire on the heavy side does a good finishing job when you have a fair amount of snowshoe traffic. Like you said, you need a good base and some side cut to hold the line. I now use my Hok skis to pack trails, it makes natural wider turns and berms. On the up trails you still need to stomp a bit to hook the skins.That doesn't pack trails. On the slightest off-camber stuff, tires and sleds just slide right off the trail. Making a tight twisty trail sustainable over the winter takes some work, berming, filling holes, making it wide enough, reinforcing the sides (the weakest part), etc. It's still a fraction of the man-hours of summer trail building. There are a few people that insist on dragging tires and sleds, but it really doesn't do much of anything useful for setting a trail. XC skis have a lot of compaction and while relatively skinny, are quite helpful.