After using Inbox for a day, here's my initial thoughts: Incredible mobile experience, but not as productive as Gmail on the browser side. If you're an inbox zero fan, you'll love it. I think the point of Inbox is to bring inbox zero to the masses. They've replaced the "archive" button with a check mark button labeled as "done". This button has the exact same functionality as archiving a message in Gmail, but to someone using Inbox for the first time, it would more natural to click "done" rather than archive. The reminders & pins are a nice touch as well.
The snooze functionality takes a page from Baydin's boomerang service. However, this is where I'm still not sold. I've used Baydin's boomerang service for nearly 2 years now. I use it on approximately 80% of the messages I send. Inbox gives you the ability to "snooze" messages, but not "boomerang". I think it's much more important to be able to bring an email back to your inbox when someone hasn't replied to it as opposed to snoozing a message to take care of at a later date/time. I've come to the point of not understanding why you would even attempt inbox zero without boomerang. It blows my mind that email has been around for this long and we're still relying on a third party app to achieve this functionality. For anyone unfamiliar, Boomerang allows you to set a message to come back to your inbox if a person does not reply to it in 12 hours, 2 days, 4 days, or any later date you choose. I started using it for business, but then I realized how much it helps with everything. I use it on most personal emails now as well. Let me give you a real world example: 3 people on an email chain, everyone agrees we need to meet one day next week. The last email of the chain someone suggests, "Are you guys available next Wednesday at 10:00 AM?". In a world of inbox-zero without boomerang, this message may go unanswered if everyone on the chain forgets to reply (very common in my world). For a boomerang user, I set the email to come back to my inbox "if no response" in 2 days. This way, if there's no response, I can send a follow up, "So are we meeting next Wednesday or not?" I still can't figure out why this hasn't been built in to more email services by now.
Anyways, coming back to Inbox. It's beautiful, cool, great on mobile, but I will not be able to use it as my main email client unless they allow 3rd party apps like boomerang. Or, for the love of technology, build their own functionality that brings no-response emails back to the inbox! Am I the only one?!