When doing a tag on an Activity Feed Post, using �@�, the search experience is poor:
1. It takes a long time to retrieve results: at least 7 seconds in our v9.0 instance which contains very few data for now.
2. If the user continues typing, a large number of parallel requests are resent as the user types in the characters, and it seems slow and laggy for the user experience.
If the user is typing slowing, this represented hundreds of parallel web calls.
3. The results are not presented in a relevant order: for example when I just want to tag another user and I can�t see her in the presented results.
4. The number of entities that are searched is too important: almost all CRM entities, whereas we should be able to limit it to just a few relevant ones.
In my tests, queries to CRM entities are run two times: around 90 times with no filter apart from active records, and then again 90 times with the searched string.

It would be good to be able to tag other users quickly (for example to draw their attention on specific CRM record).
Right now the experience is really poor and too many irrelevant record types / records are presented, probably because they are owned by the searched user