I ran the RC1 for my own environment, and found the upgrade process easy and seamless. Very few issues - actually just one, which was a bug which was quickly fixed.
Today I upgraded (well, converted over) two clients, and had no issues.
One was an inhouse VMware install, the other was at Vultr (recreated new VPS on Debian). Now planning a larger deployment across my other clients. We only use PJSIP (saw the writing on the wall years ago), and we have nothing really custom that Asterisk 21 would break.
how the heck are you finding time to do the upgrades? My customers seem to never have down time during the day or the homelife doesn’t allot me enough time to work on work stuff.
Kids and wife got to make sacrifices to keep their lifestyle intact. I charge about 3 hours per Vultr redo, and 4 for in house installs since I have to install Debian. I was literally doing 2-3 a time every day for the last 7 days. I build it out, restore, disable the trunk on the new system, then decide on a time to cut over off-hours.
Edit: I generate and restore just the voicemail backup right before I go live.