Same here, first time with Viking on a 737-300 to Kos, and its was a great service and better than First Choice who I travelled with last year, plane was cleaner and there seemed to be more leg room(just about probably an inch or so) only thing is they do not have TV's/Radio so take your own Ipod etc...
Staff were very good, was worried due to reviews I had read but will definately travel with them again.