On iPad and iPhone, the experience feels a lot like Google's Inbox. Swipe right on a message to Schedule (Snooze), Swipe Left to Archive. The motions are reversed from Inbox however they can be customized in Settings. The iPad app gives a reading pane, much like the experience in every other iPad version of a mail app.
I'm on an O365 E3 plan with online Archiving, and the experience is much like Exchange ActiveSync. No Online Archive is available (I'm not really sure what the Archive action is able to accomplish in this regard, it certainly can't send something to the online Archive, and that's not how that's supposed to work anyway). Also, I'm unable to open another user's mailbox. For a variety of use cases, OWA is more functional for me. I think the Outlook App will shine when adding multiple accounts and using a single pane of glass.
I will say that Autodiscover worked in SECONDS with using my userPrincipalName and password, which Apple's Mail app typically chokes on (have to specify O365 server endpoint, specify username format)
So what is this App using, really?I'm an O365 admin, so I am naturally curious how this App ticks with regard to Exchange.
In the Exchange Admin Center (O365), under Mobile, we can set Device Access Rules. The Outlook App is a Device Family and Model, as shown:
Hooray, now what service is the Outlook App using?
From what I can tell, the Outlook App is an Exchange ActiveSync Device. It should be using the default EAS policy (assuming you don't have some sort of rule that applies a different policy by device model/family). Get-MobileDeviceStatistics clearly identifies the Outlook App as ClientType: EAS. It also shows DevicePolicyApplicationStatus: AppliedInFull (Yay!)
I tested by setting a Wipe on my Outlook, Outlook for iOS and Android "Device" in EAC:
This first exhibited itself as an authentication failure in the app (on both devices, strangely enough). I closed the App (swipe up to kill), and re-opened it, to be greeted by a Deleting... action and then the initial setup wizard. Sounds like Device Wipe works well enough! It didn't touch the actual device, naturally, making this perfectly suitable for BYOD. Even though both devices I had using this "profile" are wiped, the wipe still says pending in the console. I've cancelled it so I can move on.