I've played many times and it works great. Def worth having someone in your common circle that participates a lot to purchase the additional member pass (up to 4 players is free). The only thing is that it doesn't take into account extension pack rules for higher number of players but to me that's barely an issue let alone a deal breaker.
I played JSettlers a lot, ages ago. The (free) host moved around a bit, so would lose its critical mass of players. Looks like it lives on here: https://github.com/jdmonin/JSettlers2
I haven't tried colonist.io (cited in other reply), though from a brief peek it looks very polished. Am eager to try it.
TTS is a real last resort. It's the "Let's try hitting it with a hammer and see if that fixes it" of ways to play board games.
I have an ongoing Gloomhaven campaign inside TTS. 50% of every session is people wailing and yelling as stupid things are simulated that we don't care about. Oh you dropped that piece on the edge of a piece of cardboard so it fell over. Oh you put this token at the wrong angle so it doesn't count. Ugh.
When the same group of people play anything else we play it either in dedicated software or in https://boardgamearena.com/
Unfortunately BGA doesn't have Catan though its management have said they would cheerfully pay to offer Catan.
I've played many times and it works great. Def worth having someone in your common circle that participates a lot to purchase the additional member pass (up to 4 players is free). The only thing is that it doesn't take into account extension pack rules for higher number of players but to me that's barely an issue let alone a deal breaker.