noob question: Whats the difference between 1, 2, and 3 piece backs? Is it just durability?
1 peice backs are not common because trees large enough to get 1pc quater saw billets from are very few and far between. To get a 1pc back for your average dread, the tree it's cut from would have to be over 3ft wide. Thats a big tree.

There isn't much difference between 2 and 3 pc backs. It's really just about looks.
Not taking any online orders.
I've heard that sound quality might be affected by having less sustain and it might sound thinner.
I personally couldn't hear much difference, but the durability is difference. It's just like 5 piece necks or whatever,