I'm not near ready to delve into the UHD/4K realm, as my main cams are still the HVX-200 and HMC-150. However, this new unit by JVC looks interesting and may prove helpful to me.

My concern is that the press release includes a line that this should work with "most" cams that output HDMI.

Any ideas about how can I tell if my HMC is compatible? I don't want to go through the buy-and-return routine, and I don't want to put a vendor through it unnecessarily.

I realize I'm a year late in answering but I'll try anyways.

Consumer Blu-ray is far inferior to even Sony's Professional Disc and XDCAM. (nearly the same laser wavelength, different technologies)

You will get much better results out of something like a Blackmagic Video Assist in DNxHD mode. If you think SD cards are too unreliable, a Hyperdeck Shuttle would ease your concerns with the proper SSD installed. (and with the latest firmware update)

As long as your camera has an HDMI out it will work with both of these, but the HVX will need analog to digital signal converters for the component out from the HVX.