In my opinion AA is the clear winner, at least if you are flying cheapest possible economy. Here are the most important points for me:

- you earn miles on pretty much every AA, BA, AY flight, no matter the booking class (for example AA's flights between USA and South America in booking class O don't earn miles on any other OW program)

- you earn full miles on Flybe flights

- I'm not sure, but I've understood that you even earn full miles on AY's leisure flights

- you can book one-ways from HEL to most important European cities for just 10k miles +tax

- 25k miles (first elite level) is easiest to reach with AA's program of all OW programs

As you have noticed yourself, AY Plus sucks, so please don't even consider it