I never even thought about plunge cutting with a jigsaw until I read this thread. I tried it this weekend with my Dewalt and it worked awesome. The guard on the front appears to be made to do it, and it sure felt like it when I cut. The first 2 times I tried it in the middle of the wood, but it worked so well on my final piece I plunged right on the line and it cut perfectly!
I carefully and slowly tried it with my el-cheap-o skill and almost instantly bent the blade.
Again, I quickly figured out that the el-cheap-o skill is a rough cut saw, the dewalt is precision piece of wood working equipment!