Ok. Google Plus is now so busy that I can no longer keep up. I came down this morning to an estimated 500 screen fulls of un-viewed Stream posts and comments. So I'm going to have to put some effort into Circles and only watch a few of them. Which means I'll probably end up missing the Signal nuggets in the Noise.
Meanwhile, I only had one notification over night so like Buzz before it comment streams are getting lost by people and forgotten in a day or two. At least Buzz had a stream for "posts I've commented on" so you could go back and look at old posts and continue them, but even there comment streams would often come to a halt in 24 hours or so. Quite often I'd find myself being the last person to comment, not because I'd killed the conversation but because people didn't go back to look.
I really hope Google is building tools to help us consume more and ignore more. A collapsed comments view with just the posts and comment count would help. And also tools to bring us back to conversations we're involved in.46-71 Trinity Rd, Ware, Hertfordshire SG12 7
The danger I see with every man and his dog arriving in this space is that those of us with a passion to connect to as wide an audience that is relevant to us or our interests, is the noise level you have experienced as many of us have.
If Google+ get some kind of filter tool for us to configure as we require, that could help a great deal otherwise many of us I suspect simply will not have the time to digest all we are being fed.
If you spread yourself too thin and don't spend sufficient time on any one or two platforms, your messages disappear into the ether as quickly as they were posted!
Places I'm active today are, Google Plus, A Twitter List of everyone in motorcycle racing (read only), A Facebook list of just my friends, One Skype chat, A couple of low volume email mailing lists. I've pretty much run out of time to read feeds (my own reader rather than G-Reader) or any of the special interest forums. And of course Ecademy for work but that's mainly professional interest rather than any actual participation. The key here is that the only general purpose discussion I'm following at the moment is G+. Everything else is very niche interest and directed. And as the OP says, G+ is now too much so that's going to become niche as well.