Yes I do, on one Mac, but not the other.
Thanks for asking. I had forgot about this.
Looks like Growl provides more control over the notifications.
For example, I can set the "Action Failed" notify to "Always Stay on Screen", and use a different display style.
Whereas with the Apple Notifications, I am forced to either make all KM Notifications "Stay on Screen", or none.
So my vote would be to keep using Growl.
####Growl Preferences:
