Thanks for your report, Swiss Tony. My conclusion is about the same as yours, having flown CX J a fair bit, although not so much in BA CW recently.

I thought BA's CW food was the weakest point until I encountered CX's J food, especially the main (appetisers are generally OK). It's often an uninspiring small-plateful of semi-tasteless slop that I eat just because it's there and I'm bored.
I find this rather interesting because CX's F food is far better than BA's F food.

Then there are the 'old' CX J seats. I recently had the displeasure of flying upper deck in the old CX J seats. I do not wish to repeat the experience. The ceiling felt very low and I almost felt as if everything was closing in on me (I do not have that problem on BA CW window seat or CX F in the 'nose' section downstairs). The old CX J seat downstairs felt better due to the feeling of more space (not in the seat but the environment).

The new CX J seats are much better than the old CX J seats, though.

(Talking about long haul only here.)