Sound observations
My flying patterns make my conclusions different, but the substance of Jasper's message is accurate. For a Canadian, AA is not the obvious choice. One reason is that most trips begin with a flight to a US hub, while AC offers nonstops from its hubs. Living in Toronto, AC offers better routings and total travel times than AA.
For me, AAdvantage is the difference that keeps me with AA. No scamcharges, cheaper redemptions (J to Asia is 110,000 on AA, but 125,000 on AC and rises to 150,000 in January!), F lounges (BA F in BKK is yummy!), 100% bonus, SWUs applicable against the lowest fares: these are the main attractions.
My flying is all leisure, mostly to Asia. 5 trips to BKK make high status easily attainable on AA and all my SWUs have always cleared. I agree that the old J seats on AA are crAAp.
But the numbers tell the story: on AA I can buy the cheapest fare every time (usually $1,500 YYZ-BKK), earn nearly 40,000 RDMs on each trip, pay only $124 in taxes when I fly on points, in J, on Cathay. Total annual cost on AC would be higher and the average class of travel lower.
Now what am I gonna do with my 250,000 Aeroplan Miles?