A coworker wants to shoot in a studio with three cameras and asked if their is a way to shoot with the HVX to record onto a computer. I told him that it does not have SDI out. And that a camera that has SDI out might be better. Is that correct?

I think you're confusing two technical options together.

Yes, you can record directly to a computer using "capture now" in FCP for example either to a laptop or desktop with FireWire. There is some hardware available that would allow for a multi-cam firewire capture but it's pricey and requires some technical expertise to setup - of which I've never done. Talk to Ron @ Abel Cine about that; they sell the hardware and have setup guides available.

With respect to the SDI out, the difference is that if the HVX had one it would allow for uncompressed captures, as it is the best you can do is get DVCPRO-HD out FireWire to your capture system.

Hope that helps.