As a vegetarian, I would have probably ranked this restaurant with four or five cows. But, as a vegan, and because of the excessive use of dairy products (in almost every of the interesting dishes) and the lack of vegan alternatives, I definitely rank this restaurant with two---unhappy---cows.
The restaurant offers unlimited hot and cold vegetarian buffet (including different pies), unlimited soup and unlimited dish of the day at a very reasonnable price. The staff is friendly, but is not really aware of what veganism is. The location is convenient if you work around and the place very nice with a big terrace. However, as a vegan, it is not really good value for money because there is very few choices, only in the cold buffet, with some items having a flavorless taste and some others being very good (such as their moutabal). Moreover, vegan choices are not clearly indicated. The only dessert you can have is a fruit salad for 1 euro.
Concluding, go if you're vegetarian, avoid if you're vegan. Needs major improvements to be interesting for vegans.
Cons: very few (not labelled) vegan choices, staff not always aware of veganism