Proxmox vs Xenserver.org - Thoughts?

I'm helping the local public library convert 5 various physical servers (4 linux web servers and 1 windows email server) to 2 locally hosted VM servers.

In my lab we use VMWare ESXi with all the expensive bells and whistles, all way beyond the library's budget.

So they're looking at either ProxMox or Xenserver.org as their VM host.

We understand both have support fees, but they are within the library's budget.

Key factor is easy management (they don't have a staff IT), the ability to make running snapshots (preferably without taking the VM guest down), and the ability to backup those snapshots to an external storage host (i.e off server backups). Of course it would be nice if they have some P2V conversion utility, but it's not a must have.

We have the two VM Host physical machines built, so plan on installing both and see how it goes - but I thought I'd ask here to see if anyone has any experience with either platform. I've played with Promox in the past, but always returned to ESXi - although I hear many good changes have occurred with Proxmox in the last couple of years.

Thanks and don't forget to SUPPORT YOUR LOCAL LIBRARY.