I have been using Proxmox for many years now in my home environment and it has been nothing but rock solid.
Use ZFS block devices for all guests and a specific pool as file storage which all guests access over NFS.
It´s rich in features and easy to work with. Configs are also easy to find and access in case of any issue.
Only reason I don´t use it in our corporate environment is the backup features. The limitation of only full backups makes offsite copying problematic with large VMs.
ZFS can solve this problem by sending and receiving snapshots but you need to script it your self or use an external library. I use this method to backup my NFS pool but its not robust enough for VMs.
Other pros,
Guest firewall
Cons,
Subscription nag screen
Guest console can be a little dodgy sometimes
Note I´m using version 4.4 so some of my issues might have been resolved in newer versions.
