Are there any major differences between the two(away from the price)?
A Nucleus is a device that can only act as a Roon core. The SonicTransporter is able to run other apps aswell. An important feature would be HQPlayer, that has advanced upsamplling functionality. It also can run other playback software, which will be handy in case your internet connection blacks out and you cannot play your local files anymore via Roon.
But if you are into Roon only, I do not think that there is any major difference.
Thanks. I just to ensure i wont loose any of Roons functionality with the SonicTransporter.