As for the cost factor, a lot depends on your budget and what you are willing to spend. The prices listed (unless I misread) are $500 and $1000. OR, twice as much for a higher class.
IF you are on a tight budget, then I'd say it isn't worth the difference for a 10-12 hour flight. The money would be better spent DURING the trip rather than the getting there and home.
BUT, if the budget is looser and $500 is NOT a large sum, then go for it, as it makes the overall plane trip more enjoyable.
RIGHT NOW, my own budget is tight enough that I wouldn't do it. Yet, my uncle travels a lot for work (he is a film director of photography) and has the production company fly him first class as part of his contract, wouldn't have it any other way.