I think you mean Virgin Atlantic (VS) as Virgin America has ceased to be. Personally I have flown both CX and NH first class (old version) and I found of them both to be excellent. I would probably go with whichever one was cheaper/allowed me to use points I needed to burn/had my preferred schedule. If new version of NH first was in play I might have to think harder. Also as noted it is possible some airlines may not make it out of this. I consider VS and CX "higher risk" than some others. Not a huge deal but I'd probably make sure I had refundable reservations/travel insurance just in case. Keep in mind if you transfer your UR to VS and they cease operations you could very well lose your points and your tickets on NH.