I'm experimenting with a Warbonnet Blackbird hammock for solo trips, and so far I'm liking it better than ground sleeping. Hammocks will not be an ultralight shelter solution (my hammock weighs 24 oz plus a 4.5 oz suspension). My OES tarp (MacCat Deluxe in SpinnUL) weighs about 9 oz.
The payoff for me is sleeping comfort and more flexible setup options (don't need level ground!!). This past weekend I coped well with 35 mph winds and rain, staying warm and dry. While at a campsite, lounging about in a hammock beats almost every alternative I've found! The Blackbird (like some other models) is designed to permit/encourage sleeping at a slight diagonal to the axis of the hammock, thus permitting a flatter profile for sleeping. It does work!
Hammocks don't insulate well and need some pad and/or underquilt for cooler temperatures. My Neoair inserted between the double bottom layer on my hammock has worked well down to 50 degrees F. (so far) with a 35 degree WM Caribou sleeping bag inside the hammock.
I don't consider my experiment complete but so far, hammock camping is my shelter of choice over traditional tarptent options.
hammockforums.net is a good resource for learning more about the many choices of hammocks/tarps/suspensions/techniques.