If I might bring my humble opinion on the matter: I've seen CoF headlining once in Paris on the Midian tour and it was rather disappointing I must say... Boring concert, no spirit, no life, no energy... Certainly nothing to compare with CoB, which always (at least the couple of times I saw them) put on a crazy show! Anyway, I'd still recommend you go to the Porto gig, since Moonspell will be playing home and that's a hell of a band!!! In fact, they're the only reason why I'm going to the Stockholm gig