I was in the first wave of Google Inbox users when they started leaking it out into the world. I can't remember when that was, but I've been using Inbox exclusively now for at least a few months. I'm done using it now and am moving back to mail.google.com and native Google gmail apps.
Let me start by saying that of the three application protocols (HTTP, SMTP, IMAP) in the world that actually matter, two of them are email related (the latter two). The lowest common denominator implementations of said email protocols are the only impls that matter, and the same goes for email clients (web or otherwise) implementations. Google knows this, and so I thought they'd get it right with Inbox. However, the vi shortcuts that gmail has leveraged for nearly a decade now, don't work in Inbox. I thought I could get along without them, but, I can't. I can only assume the hardcore email client engineers on the mail teams in Google are revolting against Inbox's high-level email abstraction UI metaphors, and therefore the shortcuts aren't being prioritized in Inbox. I suspect they eventually will (it's just not that hard to build them in), but until then, I'm back on gmail proper clients.
Inbox got a lot of things right.
- cross platform xhtml (or whatever the trendy buzzwords are for it today) libs that work consistently across a variety of platforms. I've been really impressed by this approach. Use it.
- auto-categorization is nearly 99% accurate.
- I like the category/tag grouping it does in the UI.
- Snoozing email is an awesome UI metaphor.
- Marking as "done" feels better than archiving.
- Swipe UI metaphor for dealing with messages feels correct.
Inbox got some key things really wrong.
- Search results presentation. Trying to guess which results are most relevant for me, and presenting those first, has long been a broken approach. Don't do it. Give me chronological results. I know how your search algorithms work... let me drive from there.
- Search operators. I spent years mastering these, don't take them away from me. You're a search company first and foremost, don't forget that.
- select/copy. Selecting text in an email and copying it doesn't work on iOS.
- And the biggie... keyboard shortcuts. Few if any of them work.
- GUI state refresh. Going in/out of the iOS app causes full GUI state refresh causing me to have to reload searches and find scroll positions again. That's a bug.
For a general email user, I suspect Inbox is pretty sweet. As a power email user that uses the keyboard a _ton_, it's not so good. Let me know when the above list is fixed and I'd happily give Inbox another try; in general I like the new UI.