I'm a fan of the upper deck. It is quieter and has less foot traffic than the LD C. I love the window seats with the lockers. And it is much more private up there.

17A is my all-time favorite; nobody behind you tugging on the seat through the night, 3 lockers that both hold my stuff in them, hold my feet up on them, and serve as a great place to put my notebooks, reading book, files, pens, water bottles, etc. through the evening and rather than being held captive by the FA's waiting to take away my dinner tray I can always put all that stuff on the lockers to use the lav or just keep working on my laptop. I always use the upstairs closet for my rollaboard, never have been refused.

As for the FA's, it really depends upon the FA. I agree that the HKG station has the best FA's on average, but my recent SY-SFO flight with and SFO crew was really superb, I was pleasantly surprised. (They both get a 2-4 hour break midflight and sleep in the sleeper cabin in the rear of the plane).

I definitely always choose the upper deck when available if the seats are window seats and not those icky bulkhead seats. And I have gotten great seats up there throughout the upgrade cycle, from confirming at booking 12 weeks out, to being the last to board and awaiting that golden ticket, so they are not always gone first, especially when they start breaking connections due to WX, all sorts of good stuff pops up!