I have eaten at Chandni Chowk twice - once in the restaurant and once for home delivery.
Atmosphere
The atmosphere at Chandni Chowk was, well, interesting. The mud walls and stone seating contrast with the bright colors, glitter and mirrors, and Bollywood pics. It is definitely different. We would have found it a lot more fun if the seats hadn’t been so uncomfortable (that’s why we opted for home delivery the second time).
Food
On both occasions, the food has been great! If you are a non-veg, you must try the sheekh kabab masala - so delicious. The tandoori chicken is also very good.
Price
The price seemed a bit on the high side. But, then again, you’re getting what you pay for - really good food. An order of kadai paneer costs about 80 rupees, veg biryani costs 70 rupees.