3Par Recovery Manger for vSphere is terrible product.
1. Application itself is terrible, requires everything to be scheduled under one account.
I believe this is fixed, storage credentials are now separate from windows account but haven't yet had a chance to take a look.
2. If you want to quince VM via VMware tools to have application consistent snapshot there is a limitation - up to 8 VMs per datastore (read VV).
Not sure if this has been lifted but I do remember 32 being mentioned, also you still have the option to do this on a per VM basis.
3. You need additional licensing if you want multiple point in time restores.
This is incorrect virtual copy is all you need for multiple snaps and point in time restores. Virtual Lock provides immutable snaps for compliance. The wording could be clearer in the manual to avoid giving this impression and I believe it is in the new version.
4. Compatibility issues
This is the way pretty much all hardware based snaps of VMware are integrated, Veeam / Netapp etc. All first require a VMware soft snap to provide a consistent on disk point in time and then the hardware snap is taken. To avoid the soft snap diverging it's deleted once the hardware version is in place. Since snaps are interdependent if you have multiple services creating and arbitrarily deleting soft snaps on the same datastore then your going to have issues.