What we found out the hard way is that an RBC Visa 2-4-1 avios voucher is only valid for trips which start in Canada. So when we tried to book our flights home and they had all gone around Christmas, we tried to route via Chicago or NY. Not allowed!!
With the dropping of Calgary, that leave a total of four daily flights - 2 x YYZ, 1 x YUL and 1 x YVR. Annoyingly, BA started selling (including avios flights) on 2 x 787-8 from Toronto which I think is the smallest LH aircraft. Now, a 747 and 777 (and 2 x 747s today) are operating the route where the downsizing of the supply of seats for the winter (and NO first class) due to the 787-9 issues may have been too extreme and they've had to add capacity. I digress!!
We fly twice a year in J or F for a little over 1000 bucks each. The high fees are mainly out of BA's control. We still see it as good value, though the vouchers are triggered after 30k bucks is spent in a calender year means that (depending on how much put on the card a month), there is a rush to secure seats for Christmas between May and July. Similarly, you almost need to hold onto a voucher for the following year so you can book summer flights the previous summer
We think it's worth it as we would rarely pay for a J or F flight out of our own pocket