I tried it and to me the main problem with going whole-hog to a Google Calendar app is that I don't think a platform-specific calendar app can ever be as effect

I tried it and to me the main problem with going whole-hog to a Google Calendar app is that I don't think a platform-specific calendar app can ever be as effective as a platform-agnostic one like Sunrise. All things social belong to Facebook, so using a calendar that isn't linked to Facebook events is a non-starter for me. Similarly, travel plans tend to belong to Google since I use Gmail, so one that isn't tied to Google accounts would never work for me either. Execution and visual design is fine, but I think to most people it's secondary to functionality. If the app is causing a large portion of my events to be disregarded, I'm not going to use it no matter how pretty it is to look at.