In case you haven't seen it,
http://tothewoods.net/HammockCamping.html is a great reference tool for folks new to hammocks.
For me, I wanted to swich to hammocks for two reasons:
1. Many hammockers use an underquilt for their hammocks to provide bottom insulation. These are more compressable than the foam pads I use when I am ground camping. So, I saw an advantage in compactability.
2. I feel that hammock camping is more versatile than ground camping because you can now select sites without regard to the slope of the ground. Roots and rocks don't matter, either. And, you don't have to go through the process of moving sticks and cleaning up the ground, as you do with ground setups.