Mostly capacity, the same way it works on the physical side of the lineup. The 950Vx scales up to 28 TB and around 4,000 mailboxes, well past the 850Vx's 2,500-user range, while deployment options, RAID choices, and licensing stay consistent between them.

It does for a lot of organizations, especially ones that already run their infrastructure virtualized and would rather not manage another physical box. The tradeoff is that performance depends on the resources your host can dedicate to it, so at this scale it's worth confirming your virtual environment can support sustained, heavy archiving traffic.

Yes. Federated search works across the entire environment, so the 950Vx can search alongside older physical or virtual archivers you're still running, whether that's during a migration or as a permanent multi-appliance setup.

Yes, both run continuously on the 950Vx and cover firmware, security patches, and support rather than physical parts replacement. They renew annually, and a certified rep will lay out exactly what's included in your quote.

Yes. One subscription covers the 950Vx no matter how many of your 4,000 recommended users you're actually archiving, with no additional per-mailbox charges.