A bit of story regarding our setup :
We've been running Veeam for the last 2 years, Started with Vmware as our Virtualization layer and then changed to Hyper-V last year. Either way, Veeam has been running perfectly for us. Switching from Symantec to Veeam reduced our backup windows from 10 Hours to a maximum of 1-2 Hours! Symantec was only backing up data only compared to Veeam backing up the whole VM! Also loved at the time how we were using Direct access when we still had our ISCSI SAN.
We then changed to a SAS SAN at the same time of moving to Hyper-V and had to change to On-Host Backup Proxy for our backup (V6.5). The First full backup was a bit Slower compared to Vmware Direct access but incremental was nearly the same.
The only problem we had on V6.5 was how Veeam was backing up VMs sitting on Hosts not owning the CSVs. All data was processed only by the CSV Owning Node and transferred over the CSV network to the Veeam Backup Server. The speed was still acceptable for incremental backups but it then seems that Veeam wasn 't able to change the CSV owner for VMs on node not being the CSV owner. (3 Nodes Total, 1 Node owning all CSVs, Veeam Backup Server sitting on node not owning the CSV)
Version 7 seems to have fixed that as upgrading to V7 forced a Full Backup and although I wasn't checking the Backup as it was running, when I did checked it, it was already completed to my surprise

Pictures are worth more than words :
Version 6.5

Version 7
