URLS are messy

[imaginator]

https://angular-demo.buddycloud.org/#/user/angular-xmpp@buddycloud.org/posts

would be nicer as

site/<channel>

eg: https://angular-demo.buddycloud.org/angular-xmpp@buddycloud.org

I believe the try_files $uri $uri/ /index.html; will mean you can loose the hash and be better indexed too.

[robotnic]

If URLs are messy node names are messy.
If the node name has redundant information, why is it there?

Additional default nodes could make client-developers live easier:
/user/robotnic@buddycloud.org/recent
/user/robotnic@buddycloud.org/feed

[imaginator]

I don't think it's a good idea to include "summary nodes" under the /user hierarchy. Instead, @lloydwatkin created /firehose (authenticated and unauthenticated) to give you a recent feed.

/user/<jid>/<node-name> seems quite sensible to me and leaves scope for future expansion to /other/<jid>/ unenvisioned types of services.