I'm not sad about it, turned out really well for me.
I believe the compelling part of the current offering is the schema management features. We started building these when I was there. I don't know to what degree the alerting part of the APM product survived. It was originally requested by an enterprise customer and I re-implemented it on-top of Druid to make it much more scalable. My assumption is that should be a bit of a draw. etc.