No knowledge about both devices, but as you also ask about the media:
DVD-RAM can be written 100 times the limit number allowed by DVD+RW, as said in the specifications.
DVD-RAM can be more stable and (in theory, at least) last longer than DVD+RW (time span).
I don’t know if the 2 recorder allow the VR recording format (or only the VIDEO format for DVD), but it is more likely that you get it with RAM. This can be of interest if you want to edit the video files in a computer. If the editing software allows it, VR will make you life easier and maybe produce better results.
I have got a Sony that can use both +/-RW (not RAM) and only -RW allows the VR recording format.