I had the chance to conduct a couple of unmoderated user tests with Solid. For us it was both a test of our prototype as a well as a test of the tool Solid and unmoderated user tests itself. Talking about the latter, I was positively surprised. We gained valuable feedback from those tests. As a surplus, it was easy to organize the tests and to evaluate them afterwards. In my opinion these are the two best arguments, why you should give it a try as well!
Curious to see how the journey of Solid will continue! :)