I tapered - half-caf for awhile, then switched to herbal tea. I never did just decaf coffee though - taste was too bad. I've been off caffeine now for about about a year. My biggest problem is that it's awkward at social gatherings, so I usually have herbal tea in those cases. I can't say how long it took to be back to baseline because I tapered, but my sleep has improved over the last 12 months for sure.

I feel less stress after quiting, but hard to know if it's the coffee or other factors. Good luck on your coffee free journey!