Only you can tell whether it is worth it because only you know what else you would do with that money. For me the question doesn't arise because I don't have the sort of income that can afford it but for many other people the extra is pocket change. When I have been upgraded (either opup or using miles) it has been very good. On some routes with an A340 I would say it isn't worth it as the seat reclines a bit more and a bit more leg room but that is it (I got upgraded DXM SGN and the man sat next to me was really unimpressed for what he had paid and I had to agree)