Termux is a bit of a different concept to JuiceSSH. Termux is just 100% terminal, you can install packages through apt in the command line, use standard Linux utils from your phone and on the local file system. It has no GUI.

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.

Another commentor expressed it, but JuiceSSH is proprietary. In most cases open source is more of a preference for me than a necessity, but I may need to sudo or access root over SSH, and there's no way to review closed source code. JuiceSSH (IMHO) has too much control over my computer for me to use it based on the assumption that I fully can trust the developer.

Proprietary app, so it's a no-go.

I haven't tried JuiceSSH, I use CM and only have F-Droid installed (not play store). Most of the reason I use termux is to get away from proprietary apps (I can run all free software on a server and SSH into that).

Sorry that I couldn't be of more help!

Juicessh has implemented mosh but stops just a bit too soon.

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.

Seconded. I'm reasonably satisfied with JuiceSSH for light sysadmining.