Related question, which I don't think is worth a new thread:
If you book premium eco with a connecting flight within Europa (random example IAD-CDG-MAD) in what cabin will you be put on the European flight? Premium Eco (that's Business Class with no middle seats blocked, right?) or normal economy? And what if that European flight is operated by a carrier that doesn't have a Prem Eco cabin, for example KL to AMS or AZ to FCO?