Looking at taking a positioning flight on Vueling EDI-BCN to catch another flight the following day. Same flight but prices differently across 3 websites Vueling < Iberia < BA. Any advantages or disadvantages? I'm Alaska/OWE but occasionally transfer Amex points to Avios but not frequently so not really chasing points. I'm also a little worried about bags. my roller bag is 57 cm vs 55 stated limit and it won't be jammed but will exceed 10kg. How strict are they?