Yep; I didn't realize that was how it worked until I was already committed to building up my miles on DL. A close friend flies AA several hundred thousand miles per year and he and his wife regularly get FC seats together via miles/stickers; I just assumed DL worked similarly. I realize DL's system is probably better for business fliers who fly a lot, can plan optimal times/dates for upgrades and have to book coach via work, but my work pays for FC so AA probably would have been better for me since I only care about upgrades on leisure travel with my wife. I'm going to reach DM next month and am going to see how well, or not well, SWU's and upgrades with miles work for me, if not so good, maybe get AA to match if they do that and switch to them at some point.