Hammocks are good, particularly in the rain or if you have lots of ants around. But they aren't really suited to cooler weather.

My shelter set up depends on what I'm carrying, but in warmer weather I either do a hammock under a tarp, or a brush wickup. In cool weather, I add more insulation. In cold weather (sorry, Jim, from what you've said about your climate, I'd pretty much stick to warm and cool weather configurations) snow trenches and caves, and variations there of.