Originally Posted by
avermat
Recently I asked AY+ rep if there's any reason why one wouldn't transfer Avios from AY to BA and then BA to QR to get the cheapest redemption. He said there isn't. Just book partner if it's cheaper!
I also suspect that many routes will result in more Avios when flying with airlines other than AY (but credited to AY+), as they will be earning based on the distance flown. This opens up several options for arbitrage.