I gave up running my TS3 servers (after nearly a decade) because they added a trialware system that required getting approval/serial code from the company every month to continue operating. They were squeezing everyone on TS3 trying to force them to TS4/5/etc. Have they stopped this or walked it back?
And to be clear, Teamspeak from version 5 on is not teamspeak. It's matrix with a skin. Not that that's terrible, but it's not great for running it on low power/cost VPS like actual teamspeak was.