My expectations are, actually, rather modest, and BA used to meet them exceptionally well, just a few years ago. The change here has been night-and-day; even last-minute availability, which I am fortunate enough to often be able to use, is often just not opened up because they'd rather fly empty seats than collect all those lovely surcharges. Fortunately, BA has added some flights starting late this October, and things are getting a bit better in SEA as a result.