Just to expand on the CX v BA PE, one of my fairly frequent work trips is to Shanghai, which I usually do direct on BA in PE, so I'm well placed to compare and contrast with the flight on Sunday night with CX from Hong Kong.
The main difference I found on CX was that the service was generally better delivered. It was a late night flight, same as BA, and the main priority is to get the food out fast so people can sleep, same on both. But the meal was delivered very pleasantly, and I had a fulsome and completely unnecessary apology because the FA dribbled a bit of drink on my tray table. Apart from that, it was similar: occasional patrols for water and fruit juice, otherwise we were left in peace. Oh, and you do get a proper status greeting on CX, delivered by the CSM or purser, this was universally the case on all four flights in this sequence. There seems to be a hierarchy to that too: lesser beings get a FA welcome, I was busy fuming because I'd been ignored for that on one flight when the CSM turned up a few minutes later.
I would say the food was marginally better than BA for the main - at any rate the beef fillet was medium rare - but the breakfast wasn't as good: dry scrambled egg, miniscule bacon, anaemic sausage.
So all in all, I didn't see a whole lot of difference. It's marginally better than being rammed in at the back on either airline, it's never going to be as good as any sort of lie flat experience. It was a newish aeroplane, but to be honest I rarely watch the IFE and I'm perfectly content in an antique BA 747 in PE as long as I have leg room. I think if you set expectations too high on PE you'll end up indignant - my first PE was on Virgin and I was incredibly disappointed as I recall - but it does give a little more comfort on a red-eye.
Business class on CX was another ball game completely, but that's off-topic for this thread.