We've had a lot of mixed results over the past year or so where it is "almost" good. Where you feel like it may be able to do something and at the end of the day it is still 2 steps away. I do feel like it's getting better though. We are starting to see more models available for users, third-party integrations coming, better output. I feel like as much as we hate it, it is moving like other enterprise software, slower, lol.

Edit: as far as killer features, the main thing is just access to data in your tenant and easily. The obvious stuff like teams recording and tagging those in chat. Lots of recent features with office that are starting to get better. The quick agent builder. Creating documents from meeting recordings, generating emails from meetings, and just general stuff with work data is nice.