I have worked with Terragen in the past, and I'm well aware of what the program does/capable of and how difficult is. It's nice by most people standards, just not top quality.
It's alright. The POV is a bit awkward. Is the horizon centered? The surface mapping could use a lot of improvement. The main problem with it is the fact that it looks really Low-Res. You should render it a lot bigger and sharpen it at least once in PS. Atmo looks alright but the terrain doesn't seem shadowed by the clouds.
