If you had a choice of airlines that were nearly identical in price and flight duration, from Seville to London, would you choose Ryan Air or British Airways ("also marketed by Iberia" whatever that means)? I've not flow Ryan Air before, so am unfamiliar with their service, reliability, etc. There is only a $17 difference in the fare, so I suppose the question comes down to airline comfort/safety/reliability.
RyanAir is a low cost airline so make sure you're aware of any additional costs. Follow their rules to the letter. Having said that they are perfectly safe and I have no qualms about flying with them.
What about choice of airport (Gatwick or Stansted) and convenient departure times, do they have a bearing on your choice?
Most people would probably choose BA being the more established airline, but to be honest its the same metal tube in the sky for a few hours.
I am totally flexible with departure time and London arrival airport, so I am mainly focusing on who would be the overall better airline, given the negligible fare difference.
Double check, but usually British Air will have a more generous carryon allowance and will allow one free checked bag, while Ryanair will have a less generous carryon allowance (meaning you may have to check a bag on Ryanair that you could carry on British Air), and Ryanair will DEFINITELY charge for checking bags.
This means that BA may actually be cheaper than Ryanair, unless you're traveling very light.
If equal or nearly so, go with B Air. Iberia is the Spanish airline. Could be a code sharing flight with Iberia on B Air equipment or the reverse.
On further checking, I believe it is a code sharing situation with British Airways & Iberia. I think the BA flight is definitely preferable to the hidden fees that may come with Ryan Air.
I personally avoid Ryan Air and all the carriers that advertise ridiculously low fares. Generally I stay on BA or one of the flag carriers if I can even if it costs a bit more.
The problem with Ryan isn't just that they hit you for all kinds of fees. But if you've ever had the misfortune of trying to checkin for a Ryan air flight with 200 people in line not moving with one person working the checkin you will never do it again.
The entire Ryan experience is absolutely dreadful. I'm not saying BA or Lufthansa or even Air France are great especially in coach, but they are worlds above Ryan, Go and the likes of those.
In Europe you have the legacy flag carriers, the budget low cost carriers, and then you have Ryanair, in a class of its own. Whilst they will all get you from A to B safely, Ryanair is particularly noted for offering a far from pleasant flying experience, with a deficient product in terms of passenger comfort and service.
I have flown Ryan before and it wasn't terrible. I would suggest using BA/Iberia if the price difference is that small because of the advantages of being able to check in on-line and carrying on luggage. BA and Iberia are in the OneWorld alliance and they codeshare flights.
I am definitely leaning toward the BA/Iberia flights for all of the above-mentioned reasons. The only "drawback" (if it can be called one) is the BA flight is the last one of the day to London, not leaving until 7:40 pm. But then, this just means I could spend another day exploring Seville while leaving my luggage stashed at the hotel.