Overall, the UX is thoughtful and helps with decluttering my i(m)box. I would definitely recommend Hey for people who want a more deluxe email experience (the thread/collection organization features alone are worth the price!). There are a few areas that are less polished (selecting multiple emails, and managing bundled emails, to name a couple), but the team is responsive to feedback so I'm sure it will get even better over time.
This is THE best email service I've ever used. It's easy to use, really beautiful interface, and it works the way I do. If you're looking for an alternative to Gmail or Outlook--and still need to get stuff done--I suggest you check this out.
I had Outlook and Gmail forever. Hey's re-imagining of the inbox to the Imbox and other features have given me control over email again. Bubble up feature is also very helpful.
Now I am starting to use the calendar also. I just wish companies would buy it so I could also use it at work.
Using Hey for almost 2 years for personal usage and I have only good things to say about it, I can't imagine coming back to gmail with it. It takes a bit more time to manage it later when you make it your primary inbox, which may not be for everyone, but if this essential part of your life isn't organized, you can't be as efficient I think. It's a bit pricey which may change once they have more users.
You find yourself trying hard to make it work, requires too much management, constant approval of new emails but worst of all load times are horrendous across all apps, on occasion waiting 15 seconds to load an email!