OMG, are you seriously asking this? You got 250+ posts and still are confused?
What the other poster meant is that for quicker *G go with A3 and accrue 20k mls. Then once you have hit Gold then all flights from that point forward credit to AC (Air Canada Aeroplan) for the better redemtion values. Reason going for *G on AC FFP takes more miles / longer, but reward redemtions in Asia are better (only 20kmls).
Lastly, if you call A3 you redeem A3 miles and pay as per A3 mileage redemption chart (25K in Y btw. Japan & SIN for example). If you want to redeem at the 20K level you need to call AC Aeroplan and use AC miles.