I wrote a long review, about the various aspects I really liked, the skilled application of mechanical solutions by the GMs and the fact that 4 quests are a good fit for a number of timeslots... but the boards ate it.
TLRD. It is great, good job everyone, I want to see more from everyone involved.
I will have to write a proper review at some point, but I played it on low, ran it in low tier with 6 players (they pretty much decimated it), and high with 3 and a pregen. The second group struggled quite a bit more, but it still seemed like a properly tuned challenge.
Three are quite a few things to like, unfortunately, it has a couple of flaws that prevent me from giving more than 3 stars.