You'll be in Terminal 3, Pearson's newest terminal (opened in 90 or 91), so there's a lot more glass then T1 or T2 (yet another cargo terminal that was never designed for humans)... however from what I recall, most of the bars/restaurants have their kitchens at the back of their spaces, eliminating any decent views. There are a couple of small "cart-like" bars in the gate areas, which may offer your best chance.

Unless of course you have the unfortunate luck of having a gate at the Satelite terminal (I don't think AA uses them, however). Then you are in for a 20min walk to feel like you are in the middle of nowhere with only 1 restaurant with a view of nothing.

OT: You'll probably have a chance to see the "New" T1 under final construction.... it promises to be much more 'viewer-friendly'. However, essentially only AC will be using it - even though theres not enough gates, so they'll still also be spilling into T2 - so AA will stay at T3 for a while.

enjoy! marc