Wondering the same. Also a libvirt and virsh user here, and pretty happy using commands such as `virsh snapshot-create ...`. I've used VMWare ESXi in the distant past, and from the screenshots it looks like Proxmox is maybe inspired by VMWare? So maybe a more polished and integrated GUI based experience than libvirt? Also looks like Proxmox supports containers in addition to virtual machines. Also I see from other comments that there's some features to migrate VMs between hosts, which would be a much more manual effort with libvirt.