I currently use it and it's very nice. It makes me long for a better handheld though (my 4" Moto G screen is difficult to type on, even with Hacker's Keyboard).
I can have tmux sessions running on servers with say, an irc client running, mosh in, chat away for a bit, turn it off, the irc client continues running. Perfect. Same for e-mail using mutt, notes that are backed up on the server automatically using vim, etc etc. Really nice workflow.
Give me a handheld device with ssh/mosh support and I'm happy. :)
 https://termux.com https://play.google.com/store/apps/details?id=com.termux
It's also available from F-Droid, though i recently became aware, that somehow I only had the ARM version and not AArch64, so keep that in mind. And it also works flawlessly on N.
I do not know if you can SSH into your device if connected through bluetooth.
Curious how the two compare.
Personally I like JuiceSSH because it has a nice simple UI for setting up and saving SSH connections. I like the extra buttons for things like ctrl/home/etc.
I'd definitely want something like Termux if I was using Android on a device with a keyboard, but for the sort of things I use a terminal/SSH for on my phone, I prefer something like JuiceSSH. Shame it's not open source though.
On topic, JuiceSSH also supports Mosh out of the box.
Sorry that I couldn't be of more help!
it would be great if they could support suspending a mosh connection so that you can have a resumable connection without having to have the radio on all the time.