Are you wanting to winter sow vegetables or all kinds of things? Is your goal to get your garden going earlier or to cut down on the hassle of indoor planting and then gradually introducing them to outdoor conditions?

I winter sow things all the time, but haven't done much vegetable winter sowing. Winter sowing reduces many of the problems and hassles that can accompany planting indoors or in a greenhouse in early spring. It also eliminates or at least greatly reduces any transition into the garden. However, I don't think winter sowing is a good way to get a jump start on the garden. You can get plants growing much sooner by planting them in early spring indoors. If the seeds are winter sown, and they do what they are supposed to do, they'll stay snug in their seeds until weather warms up enough for them to start growing outside. You could have decent size plants growing inside by then. I would recommend winter sowing for convenience rather than speed.