Thanks. So this is the dominance chart now for ML notifications:

Native NC > NC + Growl 2.0 > NC + Growl + Bark > NC + Growl + Hiss

Since a lot of apps still exist outside of the App Store, Growl 2.0 can't come soon enough. Though the ideal case would be Apple loosening restrictions, but ... that's not going to happen anytime soon probably.