My aversion for queues has kept me away from this de rigueur Montreal brunch destination for over two years before I yielded and halfheartedly followed my friends to l'avenue on a quiet Saturday morning.
We were lucky enough to be there before the line had fully materialized, so we were seated surprisingly fast (I would say be there no later than 10:30 a.m. on weekends to avoid insane queues).
I now understand why people wait in -20-degree weather (although i wouldnt necessarily share the enthusiasm): the food is GOOD, portions are generous and the service, genuinely attentive.
One thing I remember LOVING was their watermelon-infused drinking water.
The kids loved their french toast, and I loved my omelette (which was prepared with a lot of love, one can tell these things).
I would recommend L'Avenue for brunch provided the wait is not too long. And if it is, the wait will very likely be worth it :)