SpecsUpdate
Ranked in these QuestionsQuestion Ranking
Pros
Pro Good-looking interface
Inbox follows Google's Material Design guidelines, making for an intuitive and smart looking interface. Bold colors with clear text and intuitive actions allow for one of the better looking in house Google apps on Android.
Pro Intelligent categorization 
Inbox tries automatically bundling similar messages together. For example, Inbox will create bundles for travel information, receipts, promotions as well as group messages temporally. It enables also managing these bundles of messages together - they can all be swiped away together.
Pro Can snooze emails
It's possible to "hide" a message until a specific date and time or location, which gets the message out of your way until you're ready to deal with it. Swipe left and you can have the email disappear for a day, a week, a month, etc.
Pro Helps deal with messages quickly
Inbox has intuitive swipe gestures that allow quickly dealing with emails or groups of emails. It's possible to mark them done, archive them or snooze them for later by swiping. It allows you to keep inbox at zero messages easily.
Pro Surfaces important information from messages
If an email contains pictures, flight information, reservation at a restaurant, attachments, links, dates, phone numbers and other information that the application recognizes, it will surface that information in its main view. These items can be viewed and interacted with without having to open the message itself. It allows finding and taking action on the important email information quickly.
Pro Can add notes to emails
You are able to add notes or reminders to pinned items - very useful for long email chains when you can't remember what the main point was!
Pro Integrates Google Now reminders 
For users of Google Now, Inbox integrates with the service allowing for reminders to be seen while using Google Now as well as set through the service.
Pro Integrates realtime updates in messages 
Through a feature called Assists, Inbox offers context sensitive updates to messages. These include information such as flight status updates before a scheduled flight.
Pro Can create tasks from dates and tasks in messages 
If a message includes a date, Inbox is capable of automatically creating a task from that information.
Pro Auto replies
Can reply to emails using an AI generated response
Pro Trips Bundle
Centralized "folder" for trip info such as airline, hotel, and rental car reservations. Similar to Google Trips.
Pro Categorizes mails by Bundles
In addition to the several automatic categories, you can also create your own bundles. Thus reduces clutter and enables you to archive a whole bunch of mails with one swipe.
Cons
Con Only supports Gmail accounts
No exchange email support or importing of any other e-mail services mail.