I've never taken anything overnight from them before, but I've taken both the regional and acela on the NEC and I've taken trains on their keystone service. The cars are a bit dated but they're in the process of upgrading them(idk if they're doing upgrades outside of their amfleet cars though) and they look a lot better now thsn they did not to mention more comfortable too. The crowd was mostly white and pretty tame if that's a worry for you. Only bad things I've had are delays and mothers who ignore their screaming babies.
Much better than driving or flying if you have the choice imo