it's great to see friendlier APIs for working with email! is Inbox intended more for building email clients, compared to something like Switchboard (http://switchboard.spatch.co/) which is more for processing inbound email?
any plans for a WebSocket API? seems like it would be easier to receive pushed emails on an existing socket, than registering a webhook and then sending a push notification out-of-band to the client to fetch new emails.
Your comparison between Switchboard and Inbox is solid. Switchboard is being used for tasks like sending "new email" push notifications to mobile clients, or uploading attachments to dropbox. I haven't used Inbox yet, but I'm excited to try it out.
It's great that Inbox is also built on top of IMAP. The new Gmail API is great, but an application which takes advantage of it is locked into using only Gmail. By building from the standard, Switchboard and Inbox are cross-provider.
PubSub is definitely a promising model for future APIs. This is just the beta API release, and we wanted to get feedback on the delta sync protocol first.
any plans for a WebSocket API? seems like it would be easier to receive pushed emails on an existing socket, than registering a webhook and then sending a push notification out-of-band to the client to fetch new emails.