Thank you everyone for your reply!
If this is of anyone's interest, here is the reply from AY+'s email:
Leg space may feel bigger on rows 1, 9 and 10 on A350 planes because there is no seat in front of the seat where bed (legroom) opens. On other rows there is seat front of the seat and leg space may feel more narrower than on rows 1, 9 and 10.
Don't think it was a very specific answer...