The are two things that I really appreciate about Southwest: they have extremely efficient and reliable service, and they have never once screwed me over in hundreds of flights. Other airlines that I fly on routinely, such as American, have screwed up badly more times than I can count in far fewer flights.
I tend to value efficiency and reliability in airlines first and foremost, with comfort following a distant second and competing with cost effectiveness.
I agree, good points. Although I don't fly nearly as often as you do, they are always prompt, and I've always landed early. Once I got used to their little idiosyncrasies, or what I thought they were, I noticed how nicely everything went.