I have a daily.org file I use to capture meeting notes and quick notes into. org-mode automatically keeps it organized as a datetree. I set all my other org files to archive into a subheader of the day it's archived (or done, for todos). So far I like it, but I've only been doing it for a few months. We'll see when it gets to years.
One nice thing is it's easy to see at a glance roughly what I did in a given week or month. It also doesn't insert much process into my flow, which I appreciate.
I had a separate 'daily.txt' file for this sort of thing, and it's desperately in need of a replacement. Your setup sounds pretty good to me. It seems like org mode may be a better match for the daily stuff than it is for my notes file. I especially like the idea of archiving into a subheader of the right day.
Every morning I run `org-diary-new-entry` which inserts a new block. At the end of the day I commit this to a git repository and push it away for safety. I've got a work-log/journal going back a couple of years at this point.
One nice thing is it's easy to see at a glance roughly what I did in a given week or month. It also doesn't insert much process into my flow, which I appreciate.