I was already using tmux for session persistence, so the local echo and handling of congested networks were the two features that made me wish I'd switched to mosh earlier.
mosh does persistence better, if you're connected to tmux over SSH it'll still disconnect as your IP changes on a roaming connection (like it does on my daily commute on the train). mosh does not, it stays no matter what. Also no need for autossh or similar to reconnect when you unsuspend your computer.
I was already using tmux for session persistence, so the local echo and handling of congested networks were the two features that made me wish I'd switched to mosh earlier.