If you looked at the issues and verified they're either not applicable in your case or don't affect your application, you already spent a lot of time on it. If you do install, you should verify your app still works. If not, you already spent time on analysis. The actual installation time is next to nothing compared to everything else around the "new jre came out" event.

What I'm saying is - you should care 7+ times a year. Doesn't matter if you only update twice.