I'm not an orthodox ultralight hiker, I've just been experimenting a little streamlining all my gear down to bare essentials.

The idea behind getting a hammock is that I could make a much simpler shelter in the warm months (no need to build a lean-to). I might be able to get away with a lighter sleeping bag and no pad. If I don't have to build a shelter I might even feel confident enough to leave the axe behind. So I could definitely save some weight and more importantly, reduce the time and effort needed to prepare the camp site.