Agreed, the BlackBerry soft keyboard is fantastic - I've got it installed on my Android device and can't imagine ever going back to the craptastic Google version.
I found the Hub pretty useful when I had a Z10. I really appreciated being able to look in just one place for whatever was coming in via email, Twitter, Facebook, SMS etc instead of opening apps.
However, I'm brutal about managing my accounts - I unsub from any email service that isn't entirely essential, or of significantly high signal to noise. I also have a few people that I need to hear from but who can be ignored 75% of the time - Gmail pushes their messages a folder that I only see once I'm back at my desktop.
I keep social media accounts to perhaps a dozen or two people or entities followed, and regularly pare that list to those that I find most useful. I also quietly block people whose crap to value ratio is below a certain threshold. Including family members.
Really, if you're complaining about getting too much email to use the Hub, you're doing a pretty pathetic job of managing your communications.
I'm always amazed at the people who are on fifteen or twenty mailing lists from decade earlier, plus all of the opt-in commercial stuff from every time you shop on-line.
Click "Unsubscribe" for God's sake on anything that you know is legit.
Sadly I rely on a Canadian wireless company for service, so don't expect to ever see Marshmallow on my phone.