wenani Upgrade went smooth. I have a few servers, so it took me like 2 hours to finish everything with minimal downtime for sites, maybe less than 5 minutes in total.
Emails
I am using mail.baby for mail delivery, so I noticed emails were not sending and I could not see any mail logs on mail.baby. I re-applied the credentials on smart host and everything came back to normal.
Server Load
There is like 20% to 30% reduction specifically for RAM usage. For CPU I don't see much difference, maybe a 5% improvement.
Backup
I have upgraded after version 12.0.22 release, which made work easier for me with fixing permission. But it took a really long time to finish, like 7hrs. I always use screen so it was not a big deal to wait. One thing I noticed, after running the last two commands on the control panel v12-upgrade convert-all-bkupds and v12-upgrade update-all-website-backup-locations, the load on all backup servers went up, to around 100 on average. After like an hour or so it dropped back to 0.3. Now setting up a new ext4 for backups in future.
My rating
10/10 for me, basing on the fact that this is a whole rewrite and the kind of care enhance team has for this product is amazing.
10/10 also for @cPFence, their system working well.
