I've been using the HSC for a few days. It crashed repeatedly over the weekend, and would crash if I backed out of the app and checked Facebook, etc. I couldn't log in to the website, either.
No biggie. I pulled the trigger on this knowing it might face Harmony's troubleshooting and software upgrades.
What does cause the hub/app to crash is if there is more than one smartphone running the app. Verified carefully. I run a DROID RAZR on 4.1.2 on a Buffalo WZR-600DHP on Earthlink DSL. My partner runs an identical phone.
Harmony can win, hands down, if their software can stay ahead of the enormous hardware configurations and IMO I believe they are committed to doing just that. I have a very basic home theater: 55LX9500, RX-V1900, Panasonic Blu-Ray. Initial setup was easy and worked for a week before it began to crash the app with two Android phones running the Harmony app.
Don't give up, Harmony. This is a superb integration IMO.
Mediocrity is so common, so forgiven.