Vueling Airlines

We have not had a problem with them.

Very good airline, I use them frequently, I think it´s the first or second Spanish airline with many destinations, and belongs to IAG group, same as British Airways or Iberia.

IME, it's your standard European LCC (low cost carrier) airline. No better, no worse, than all the others. Know in advance exactly what the rules are - and know the fees that'll be imposed with little or no leniency if you fail to follow the rules of your low cost ticket - and you should be fine (though possibly a bit cramped). If you've flown on any other LCCs, I'd expect it to be similar.

They are acceptable, but watch their luggage rules. They are very strict.