I've been there for breakfast on several occasions. The first visit was for a big feast, after an even bigger night. Their vegetarian breakfast (with bacon, of course), a strong long black coffee and freshly squeezed orange juice was exactly the cure for my less than sunny disposition.
More recently though, I have popped in for a quick coffee or snack with friends and the food and service have never faulted. Their coffee is fantastic - they use good quality soy milk (if you're that way inclined), it's fantastically strong (which is always a bonus for me) and it's served quickly.
But it doesn't stop there. Two Monks is also open for lunch and their menu feature the infamous "Coburger" (Google it, seriously).
The menu is also incredibly reasonably priced. A big breakfast, with all the usual trimmings and a few extra surprises will only set you back around 15 bucks.
My only gripe regarding Two Monks is of course related to allergies. They were unwilling to swap menu items to accommodate my allergies (milk and eggs). Given the nature of their menu, this wasn't the end of the world, just don't expect this place to go all out to accommodate your foodie needs.