VS has free drinks, an amenity kit, AVOD, and good curry.

CO charges for drinks, no amenity kit, possible AVOD, and not sure about curry.

Both have sh!t for legroom.

Where CO comes in ahead is with Elite bonus miles. There is no Silver/Gold/Plat bonus for Elites when you fly on VS metal.

Personally, if I'm not after the miles, I would do VS. I've found the FAs on VS to be better than COs overall. And VS is better setup for service recovery. As an example: SFO-LHR my PTV kept freezing. After a few reboot attempts, the FA gave up, brought me a menu of movies, and asked me to pick one. He then brought me a personal DVD player with my movie loaded. ^

Mind you, VS has PTVs for Upper Class, so it's not like he borrowed that DVD player from Business. They actually load DVD players to take care of customers in the event of broken IFE.

However, if you're Elite on CO and can prebook Exit Row, you may want to choose CO. I know people here whine about the 757s, but the 757 Exit Row is probably the most legroom you're gonna get on either of the two for a TATL if you can snag it.