And then of course, you have the three major 'Alliances' which is worth considering....particularly as an airlines' own rules can bare no resemblance to another partner carrier..and if it is seamless travelling you're looking for, then do your homework before leaving home , whether that be luggage allowance.....is it the same on the next leg of my journey with a partner airline ?, are all the lounges available. ?, and if so, under what circumstances ?...and so it goes on, and on.