-I lived in Canada
-Both my sisters still live in Canada; I used to fly up to Toronto to meet them, then fly together back to Taiwan to visit relatives
-Even if I don't fly through YYZ, YVR is still the best hub to fly between BOS and TPE.

Now that BOS-YVR and YVR-TPE are both gone, I have been on UA metal. In fact, I haven't been on AC metal in more than a year. I wanted to switch to UA's mileage plus because of their much higher bonus miles and ability to upgrade with miles. However, since Star partners don't comp, I'll have to suffer through E- for a while. Therefore I decided to stay with Aeroplan and smile in my E+ seats. Lounge access/priority boarding doesn't hurt either.