I had a quick search but couldn't find this already, apologies if I just missed it.
The "VM Uptime" report for VMware tells you the Number of Reboots, Alarms, actual downtime then finally Uptime % - perfect, drops straight into a department/board report.
The Hyper-V version (guess what I use) only has the Uptime %. Any possibility the Hyper-V version get these extra fields added as well?
Also, why just VM Uptime? Why not apply the exact same statistics to the Hosts/Nodes. I'm sure that'd be just as interesting, especially in large environments.
-edit- Just noticed, you do have it but it's again only for VMware. Hyper-V needs some love!