Deborah,
Also check Vueling's web site, because some of the Iberia flights are actually operated by Vueling (which I think I remember reading Iberia also owns).
For a flight I am considering (Barcelona to Granada) , the costs are less by booking directly with Vueling, and it is the exact same time as the same flight with Iberia (so I would guess it will be the SAME plane).
What I can't figure out is if I book the mid-level fare on Vueling that includes a checked bag and seat selection, does that mean I can also take a smaller carry-on bag? Does a purse count as a carry-on, or is the purse considered a personal item (such as with US carriers)?
I asked these questions here, not to hi-jack your posting, but I am guessing you will have the same questions....either with Iberia or Vueling. Maybe someone can help both of us.
Also, for the road warriors out there who might help, I had considered buying one of Rick Steves' new smaller-size rollaboards (so we can do carry-on only), but it appears Vueling's/Iberia's size restrictions are about an inch smaller than Rick's new rollaboard.....am I wrong?