Hey!
Surface node seems to be an additive process which affects everything except the edges, leaving the edges lower than the rest of the terrain. I'm working with a tiled system so this is quite glaring, although I can just not use Surface node..🙂
Easy to reproduce, just plonk down a Mountain node followed by a Surface node, the edges look beveled.
without Surface:
with Surface:
Gaea 1.2.1.8 production