I used to fly A LOT with CX and I have now been a BA regular for the past 2 years.
Of course this is highly subjective, but I would definitely pay (out of my own pocket) 350 quids to fly CX. I find the seat to be better, with far more privacy and storage space than BA. I also dislike the BA "ottoman" you have to pull up/down to sleep and no direct aisle access. CX seat is another world.
Food I remember preferring CX, but don't quote me on this one as I rarely eat onboard anyway.
Champagne is far better on CX.
I do agree though the 777 is incredibly noisy...
That said, once on the ground CX lounge experience is another planet compared to BA. CX Business lounge is another planet compared to Galleries First, I leave up to you to imagine with CX First is...