Thanks again guys. Yes, as much as I'd love to, flying in J just isn't an option for us sadly - I suspect the "we're on our honeymoon, please give us an upgrade" line only works in the movies. Our budget for the entire honeymoon is £5k, and according to Google Flights our flights are currently going for about £2500 each in J...

Still, I'm putting as many wedding and honeymoon costs as possible onto my BAPP credit card, and it should be enough for us to get a 2-4-1 voucher - so we should get to try BA J soon. Probably not quite as good as Emirates J, but it's a start.