My wife flies this AC/BR twice a year...... BR service is great..... but communications between the two airlines are dismal!
Wife had a AE-Biz class redemption with an BR-Econ segment. Back then AC could upgrade AE-Biz class redemptions when there was available space. AE requested upgrade, AC in YYZ requested upgrade and AC9841 in BR's Biz cabin had 9 seats open (as per booking class availability and seating chart). Well BR did not recieve the upgrade request, claimed their J was overbooked and was turned down. BR said that if my wife had SWU/SSWU they would have upgraded her (which is not in the rules of the certificate)......
Well i did a print screen dump of what AC was showing in available seats and booking class availability in Z & J, timestamped it and sent to BR. Also clarified to them that SWU/SSWU rules is for AC metal only. I understand their YVR station manager met with AC.....
From then onwards I no longer see the AC assigned portion of the BR seatmap on AC.com.... My wife also liked the PE (which has to be booked under BR flight number so cannot be eligible for AE mileage accural)....
In a nutshell....BR has a great service...but dont expect much communication!