I have better mood, presence of mind and working memory in the morning, especially compared to caffeinated peers. I'm also a lot more aware of when I've woken up from a bad night's sleep (see paragraph 5).
I have much less mid-day dysregulation/impulses compared to caffeinated peers. No predictable afternoon slump either – but a rich lunch will always leave me foggy, lol. If it's the weekend, I'll often join my young kid for the afternoon nap and fall asleep in minutes – the 30-45 min nap usually feels amazing.
Coffee really feels to me now like the psychoactive substance it is. I've had anxiety issues for other reasons in recent years, and today a cup of caffeinated coffee will often trigger a good level of anxiety if I'm not physically active during the peak. The physical symptoms of both are very similar. If I'm moving about, it usually feels good, like something hyped me up, but the sensation comes on its own instead.
Anxiety greatly changes my sleep needs, and caffeine and alcohol both hid these sensations in the past, enough that I suspect I didn't have the interoception (https://en.wikipedia.org/wiki/Interoception) to consciously notice and adjust in the past, which would leave me stuck or spiraling in terms of maintenance/recovery, probably for weeks at a time.
In recent days (pretty low anxiety! knock on wood) I have sleep that's almost 2hrs shorter per night, waking up naturally. That came very progressively (sleep quality), then very suddenly (lower needs). Also a great gain, though I also aged a decade and that must contribute as well.
Note that I faded out caffeine by progressively substituting for decaf. No headaches this way (from a peak of ~4 cups a day, I would say?). It sounds like you're doing the same, which I really recommend! There's no need to self-flagellate on top of what's usually a major habit adjustment.