After watching the preview video, I immediately took advantage of the sale (since there's a refund if needed within 3 days for any reason) and I've gotten a good feel for the app and whether it will fit with my workflow. I love that I'll own this forever for one price, that's so rare these days!
The app has been running smooth for me besides when I tried deleting pictures I put in one field. The app crashed. Notified Noa and he said that it would be fixed soon.
Overall it's hard to tell what each pod is meant to do without looking at the guide, but I'm figuring it out slowly. There's also an occasional graphical issue that others have pointed out, but definitely useable and sure to improve in the future.
I'm really looking forward to the iOS app and syncing. That will help Pi fit into my workflow much better. For now I'm stuck saving things I need to access somewhere else because I'm afraid I'll need it and not have it, but it's unbeatable for quick notes and things like writing this review! Things I think I'll need elsewhere can be exported for the most part.
All in all, I feel there's a lot of good things coming for this app. Noa has been very responsive to emails and I take that as a good sign.