I used Inbox for 1 day on my phone and on my computer. I really, really disliked it. I'm just not a fan of having the app automatically lump my emails in different places. I felt like I was missing things. Lo and behold, when I went back to regular gmail, I found things that I had missed.
Nice try, Google, and I do appreciate the attempt, but I think this one is going the way of Wave.