This is my favorite restaurant, and not just because "Vegetarian" is the main section of the menu with "Non-Vegetarian" at the back. (What a refreshing change of pace!) The food is amazing enough to make up for the moderately high prices. EVERYTHING they serve is delicious; even their water is freshened with lemon and mint.
The restaurant is small and can feel a little cramped during busy times, which is why I often go during off-peak times (11:00-noon or in the late afternoon). I like to sit at their outdoor tables in summer and read a book while enjoying State St. and a wonderful meal.
If you're going for the first time, get their combination platter with a lassi or cup of chiya (chai). On your second visit, try the takari or one of the "buff" dishes.
They do not take credit card, which has resulted in a couple embarrassing dashes to the ATM for me, but the waitstaff are quite friendly and understanding. They also give 10% off for Bicycle Benefits stickers, so if you love the food but are on a budget, bike there!