You've got good points, but I think Google plus ties alot of functionality into one service, or at least it seems like that is the direction they are taking. Imagine when you can do more than email can today. Share google docs while "huddling" then turn around and post something interesting you found to everyone. I'm not saying it's the be all end all, but it's a step in the right direction.
Google+. Gmail. They can be integrated.
The bitching about having to sort e-mails and manually add filters? You have to manually add people to circles, too. And what happens when someone who's not in one of your circles shares something with you? At least currently, there's no way to filter them based on anything.
"But we can just add filters to Google+!"
We already have filters in e-mail.
I feel like I sound like a grizzled old man ("we used to code uphill both ways in the snow!") but I really don't understand how G+ is superior to e-mail.