This place (and another Govinda) constitute the whole variety of vegetarian places nearby. That means I go there often, but it does mean I like it too much.
Unfortunately, they are sort of Indian: nothing is nearly as tasty as Indian food is supposed to be, but you can find diary products in very unexpected places (they especially like adding cheese everywhere, good thing is they rarely use ghee - probably for purely economic reasons), there are days when the only vegan options they offer are rice and sausage and I remember at least one occasion when there were nothing vegan to eat at all. Bread is usually not vegan and nothing like fresh and hot roti anyway. (On good days they usually offer rice, cooked veggies, soups, salads, and even some desserts.)
It is inexpensive comparing to first-world countries (and Moscow), but in any fair comparison it does not look too good. On all occasions I can remember eating Indian fast food (set similar to rice, vegetables, dal, and flatbread) in places like Malaysia and Thailand it always was cheaper than my usual check at Govinda (I did usually leave more in proper restaurants but that's another story).
That all being said, these days you usually can find something to eat there every day and staff is usually helpful and friendly. They usually can understand what "vegan" is so you don't have to explain everything. Bottom line is: do not visit Irkutsk but do eat in Govinda if you're stuck here.
Cons: not nearly enough vegan options, not very close to real Indian food, cheese and dairy stuff everywhere