You'll get a variety of opinions. Some will do almost anything to avoid the older Club World seat on the BA A380. Others (including me) still find it comfortable. Plenty of threads on that topic if you care to dig in to them.

I'd look at schedule/arrival time/price first as the primary decision factors. If those are all quite similar, personally I would go for the A380 as I find it a far easier plane to sleep on (777's tend to make quite a racket), and despite it's detractors, I find CW more comfortable as a bed over the Collins Aerospace seat on the AA options.