I've been using Inbox at El Goog for a while now, and I am happy to answer questions (in between dealing with a newborn...) FWIW, I really like it, and use it exclusively for my work and personal accounts. Inbox functions very much more like a ToDo list than it does an email client. Here are the workflows I have: Work: I filter all mailing lists into different clusters that I have appear at 7AM every morning. I then…
First: Why do you think they created a completely new app rather than integrating features into the gmail app one by one? I understand it has a good integration of Google Now in it, but Google Now itself works very nice for me (Like showing important stuff from my gmail). Thanks!
Two apps using the same backend data (you can switch between Gmail and Inbox if you like) seems a better fit.