Welcome!
Do I understand correctly: You do recordings mobile/on the field, and move them to SONAR later? If not, then I don't see
any use for a recorder.
At least price/quality ratio should be quite decent. How much easier it is compared to a laptop + an audio interface, I'm not sure. AFAIK the file transportation via USB or the SD card works ok. I don't have experience of my own, though.