Answering for myself, not for bbeausej. We are currently using coturn. It is quite easy to setup, you have to dig a little into the configuration parameter and that's it - I would recommend it.

Oh well, you probably should use the rest api for generating credentials on the fly and think about scaling (depending on your needs).

What percentage of sessions do you see going through turn?

We use coturn as the TURN solution and talk to the Janus API via websockets (we found it much better then REST if the msg rate is high)