Not bad tbh
I have a 6GB server that averages 3-5 players, is fully modded, and has a lot of chunks loaded in. All in all, the lag is (understandably) horrible and it crashes every few hours regardless of how many people are online. I reckon without mods it would run perfectly LMAO. Also, everything is easy to use, I wish there were a bit more tutorials to follow or tips on how to make everything run smoother without buying a larger/new server. Not bad.