I think you will appriciate the versatility that hammocking offers you with regards to campsite selection. I had a friend who ran into some folks who were tarping and having bad experiences with rivers coming through under their tarp when it was raining and they were really
demoralized. Clearly, they were not choosing very good sites to sleep. Finding a good site when you are sleeping on the ground puts quite a bit into the equation: level, no sharp objects (this can take awhile!), won't flood in a rain, etc.
Compare that with hammocking, and the whole situation changes. The river now runs under
you! (You will still need to keep the gear dry, but it is much easier to reposition your gear vs. yourself who should be sleeping soundly.
) It is best if under the hammock and tarp it is relatively flat so you can best utilize the space, but it doesn't have to be. The ability to stop in many more situations is a huge asset in a situation like a thru where you can suddenly need to hunker down or just generally need flexability.