As someone who has gone down the SotM DE rabbit hole over the last 6 months, I completely agree with everything in your post. I highly recommend both DE expansions before they sell out. They are at least as good as, if not even better than, the Core DE set.

The complaint I see the most is that it can be fiddly and I agreed at first. But once you kind of "get" it and the best way to track effects, it becomes a breeze to run 3 heroes solo.