Edit: For SFM, replace garrysmod\garrysmod with SourceFilmmaker\game\usermod
Direct Link to server steam://connect/188.8.131.52:27015
Second Server: 184.108.40.206:27016)
Server Steam Group: [link]
You can also get the VSH bosses and pony maps this way. Just move the maps from the tf2 map folder to the usermod or garrysmod map folder.
Second server has a higher chance of getting the map you want as you can always vote for pony maps. Ask in-game for everyone to vote for a certain map.