Not sure about others, but I actually use the forum notifications. One issue I have is if you get multiple notices for the same post ,one for the actual response post, another for someone mentioning you if they do, another if they quote you I believe. So you can have like 3 notices for the same post. Problem is, they all need to be clicked on to get rid of them all. If you click on one notice and it takes you to the post, it does not remove the other notices for the same post. So you have to visit the same post up to 3 times just to get rid of all the notices.
It's a small thing I know.. but still somewhat annoying. I know I could just ignore it.. but then, at a glance, I wouldn't know when there are new notices. Which defeats part of the purpose of it. IMO anyways.