OK I've discovered something very interesting, yet at the same time very very annoying.
I opt for the e-mail notifications for posts by those I'm connected with and for comments. It's what I'm most comfortable with. ( I konw not everyone does it... but I do). Now, regarding comments, I've noticed something that I'm not sure has always been the case or if it changed with the up-grade. When I write a post and flag it (for whatever reason ... adult, mature content, etc.) , I do not get notified in my e-mail for comments made to that post. If I comment on a flagged post and someone comments on my comment...I do NOT get an e-mail notification.
I kind of depend on the notifications. So this is a tad bit annoying. I have to remember now, to keep it clean! LOL