Converting to Aeroplan miles (no longer possible as the transferring of miles has been abolished since last year), the point value diminishes half.

Not sure of the value in the states, transfer between GP and airlines? Is the ratio 1:1? If so, this can provide excellent value. But I think the value is using the points towards GP rewards.

Anyone know what the ratio is to transfer to BA? I'm considering this airline to book FF flights in the future.