We use snapProtect as a spool copy. I find that VMWare reacts much better to the backups using SP than without it. When there is too much I/O, VMWare snapshots get left behind. This is a VMWare bug, not CV bug. At least, it doesn't have any impact on the backup job, just annoying.
Using SnapProtect, I never had this issue. I then copy from the SAN snapshot to my primary storage. If you want/can keep some SAN snapshots for a couple days, it can really speed up the whole recovery process too and if you don't require to copy your data from the SAN snapshot to your primary storage on a day to day basis, it will greatly speed up the backup process as well.