How important is having cloud-based UC from a business continuity standpoint?

Very Important. It doesn't matter what happens at their physical location. Almost every client I have has a 3CX client loaded on their smartphone, and if the office goes down, they just switch over to their data plan and start using the 3CX app on their Android or iPhone. It makes it easy to hit the sale out of the park when you are talking to the folks that understand business continuity. Because of this design, their end customers won't ever realize if there's [a situation going on like] no power in the building because their calls are still going through.