If we were playing some of the garbage we used to play, or going to Arsenal or Man U and being pegged back in our own half for the entire game I'd be more worried.
We are bossing games for long periods, the only think that concerns me is that we have returned to a tendency to being hit on the break, e.g. when we have a free kick attempt on their goal, or a corner.
I put part of this down to Fellani going in to the box for his aerial threat, arteta taking the corner/set piece. We need to think about not being hit on the counter and then i'll be more optimistic.