Don’t forget to set your no-subscription repo!
https://thebiglaskowski.com/proxmox-ve-no-subscription-repository/
Proxmox 6.2 and newer also supports new VZ compression (VZT I think), which is super fast and super small – I can backup a clean ubuntu install (8GB) packed into a 2GB zip in like, less than minute.
As far as hypervisors go, it’s the best! It’s definitely a FOSS competitor to vmware.