Dimple, at 30th and 5th, is an Indian restauran that recently changed management, and is now owned by the same folks who own Vatan, which is currently being renovated. I've never been to Vatan.
Dimple currently has Vatan's menu and its style -- the menu is solely prix-fixe and served in courses, but you can have unlimited helpings of any disk in any of the courses. Dimple has wonderful, authentic food, and it's often food that you will not find easily in other Indian restaurants.
Dimple has a generous, open ambience with bamboo pillars inset into the walls. The servers are all dressed in traditional Indian saris and similar dress, and even the plates are authentic stainless steel, with metal jugs for water.
The food was superb. In particular, I really enjoyed the small lentil balls and the fried potato balls served as appetizers. For the main course, everything from the spinach-and-corn to the puffy fried bread was tasty, and had a fresh, homemade feel. Particularly unusual were a yellow risotto-ish stuff, called kichidi and accompanying coconut soup, which were delicious. As someone who has been to India several times, I can testify to the authenticity of the food. The mango kulfi (a dense indian ice cream) was very well-done, aromatic and rich, and the masala chai was a nice finish to the meal.
All in all, a bargain at $24.95/person, and certainly some of the best Indian food in the city.