I am thinking of coming over to Aeroplan from UA Mileage Plus due to the latter's downgrading of lowest tier elite status starting 2012. I have read this forum and the Aeroplan web site and have a few questions on upgrades:

1. After I earn some Aeroplan miles can I upgrade Y/B fares on AC via the Star Alliance upgrade award chart listed on Aeroplan.com and using Aeroplan miles? Or can I only use other airline mileage to upgrade on AC? It seems that AC does not have mileage upgrade awards (I understand that once I get elite status I will get some eupgrades), but is Star Alliance a way around this? The Aeroplan.com Star Alliance chart lists AC as a Star Alliance partner included in the chart.

2. The Star Alliance upgrade award chart posted on Aeroplan.com is different from that posted on UA.com. The UA.com chart was updated in June 2011. On that chart a one segment North America upgrade on any Star Alliance carrier that participates in the upgrade program is 20,000 Mileage Plus miles. On Aeroplan.com a one-way (could be multi-segment) long haul flight upgrade is 10,000 miles. Does that make Aeroplan miles at least twice as valuable as UA miles? Or has Aeroplan just not updated its chart yet.

3. Once one gets elite status on Aeroplan and gets the eupgrades, and presuming that one selects all the eupgrades possible on the options section, is there any way to get more eupgrades other than to fly an additional 20,000 miles?

4. There are two buckets for upgrades on AC, I and R. Is R only for eupgrades, or is it also for Aeroplan members wanting to upgrade using miles via #1 above?

Many thanks for help negotiating Aeroplan's rather obscure upgrade program!