I fly regularly on Iberia on long haul flights in coach. I've never flown AA on long haul, just medium.

I think i would prefer AA, Iberia's leg room is tad a bit stretch. On very old A330 there's none entertainment at all, just the route map. A340 are tad a bit better producing a Tail Cam and overhead LCD's between a couple of rows. Food is subpar. FA's are really rude IMHO, even though i am a young cute girl and speak native spanish.

Emergency Exits you can grab on IB as a OW Sapphire, not as straight forward as AA site, but it can be done via Amadeus. If you have a flight on A340 is just decent, if you have a flight on the very old A330 ( a la Concha Espina) it's a very undesirable experience.

IB ground service in MAD is good, at least the lounges. Lounges such as Velazquez are very nice, specially very late at night when theres none one. I would fly AA, keep a bit of the miles and use my status for the IB lounges. (if thats possible). If anyone like some Velazquez lounge pics i have high quality images on my flickr, just let me know.

For Fonebufox, yes you can pick exit row seats in IB. I did it some months ago traveling from MAD-JNB on checkmytrip.