First, I would like to express my confusion with the listing. It gives two addresses, and the name Casa de Salud, but also says it owns Casita Vegetariana. This review pertains to Casita Vegetariana which is located on Calle Restauracion. The map is wrong--the cross street is (if I remember correctly) Calle Mella. Either way, it's located on Calle Restauracion and if you are walking from 30 de Marzo towards the revolutionary monument, it is next to a parking lot and on the side of the building is painted "Restaurante Vegetariano" in hard-to-miss letters.
The food and variety is excellent, and most of the items are vegan (with the expception of honey, like the listing states). I went here about ten times over the course of 5 days. The price is insanely cheap, too--a big meal with a juice will cost anywhere from 100-150 pesos ($2.50-$3 US).
They are open until 6PM everyday of the week, with the exception of Saturday or Sunday (the guy told me but I can't remember correctly) closing at 3PM. But I did go there one day about 5PM and all of the food was gone for the day, though they were still open. So if you want to be certain, get there a little before then.
It has a buffet style with a mini health food/vitamins section attached to it. Definitely make a trip here if you are around.
Cons: Has honey in some of the items