I live in the downtown Phoenix area, love Indian food, and have NEVER gone to this restaurant for dinner. I've been there billions of times for lunch. That should tell you everything I think about this place.
The lunch buffet is decent. It doesn't vary much so I know exactly what I'm getting every time I go. Since it's the only Indian place downtown, if I'm craving Indian, this is it. It's standard Indian. Nothing terrible, nothing spectacular.
For the best Indian eats in Phoenix you need to try Jewel of the Crown (a Scottsdale oldie), and the brand new Tandoori Times (also in Scottsdale).