I agree with Fangs. NYC 7ER would definitely be the play if seniority in category is your goal. However, over the last few years, SEA 73N has been one of the few domestic narrowbody categories where reserve would occasionally go senior to a line. But, that comes with a huge asterisk as there has been a tremendous amount of turnover this past year and the category was significantly expanded on our last AE. Bottom line, I would choose the category that makes the most sense for where you plan on commuting from. Don't choose a cross country commute for some extra seniority.