I literally just got home from a YYZ-SFO-ICN / ICN-SFO-YYZ trip on United, and had to pay for E+ on every segment. The SFO-ICN legs were on a tired old 747. On that aircraft, the United E+ was no different than AC's normal Y seating on a B767, A330 or B777 (and the regular economy seating looked waaaay tighter!! Is that even legal???).

I only flew the Friendly Skies because AC was asking almost double what UA charged (nearly $4,000 versus $1,800, taxes in). Even with paying for E+ it still came out to less than half.