A few years ago i was in the same position as you: ryanair or bizjet. I would say: what is the field there are operating with xls? The biz company i was working for was flying to africa, middle east, far east, canada and other places. I must admit: what i've learned in those 3 years was unbeatable with the airline.
On the otherside, it is indeed not so easy to switch from biz to airline i think.