I'd take BA
It is a no brainer that the BA NGCW seat wins hands down versus CX's new herringbone. As a matter of fact it is not even close. You'd get superior comfort with better cushion and much less clausterphobia. Of all the new J seats (those introduced within the last 3 years) I have flown in the NGCW ranks 2nd in my favorites just behind SQ's. And among the four herringbone desgins I have flown on (NZ, AC, VS, CX), I find the CX one to be worst. So CX's new J seat doesn't even rank in my top 5 favorites.
CX wins with Chinese food but BA wins with western meals. CX's western meals has been nothing but a disgrace in both J and F the last 2 years that as a regular flyer with the carrier, I have stopped ordering western choices off the menu from them recently. Sevices on CX J used to be top notch. But my last few has been inconsistent that a BA J crew can beat them on several occassions.
So I would take BA J over CX J.