I thought I'd introduce myself. I'm a freelance joomla site developer who also built 3 moodle sites at my old full-time job. One of those was a Joomla/Joomdle/Moodle setup with about 100 students using it (some online, some onsite with an online component).
I've spent probably 200-300 work hours in Moodle over the last 2 years so I know it pretty well (though not in a large scale environment). I've been looking for an easy to use replacement that would be native inside Joomla, so Parth convinced me to try Shika.
So far I like what I see, but obviously it's pretty early on in the development so I can already find things it doesn't do that I hope are on the future feature list.