Over-rated.
My wife's grandmother is a dosa fanatic. Annually, we go to a new dosa restaurant in the GTA to satisfy her craving. For the most part, I like going to establishments that are hole-in-the-wall when it comes to dosas because number one, there are several and two, even the dives are tasty. With Guru Lukshmi, it's basically "trademarked" fusion dosas in a decor that echoes Turtle Jack's.
I had that Pav Bhaji Dosa. When I was in grad school in the US, I often had store bought Pav Bhaji (the microwavable ones) because I was homesick and desired Indian food once in a while. This "trademarked" dosa was basically that package smeared between two thin naans. That being said, the sambar was spicy and satisfying. The accompanying chutneys were good.
The service is mediocre. Beyond that, making a reservation should be a requirement. Otherwise you will be packed into a 8x8 room with 30 people likes sardines in a can and waiting up to an hour. I was thankful that I only had to wait 5-10 minutes with a reservation.
I applaud Guru Lukshmi for trying to be creative and for that alone I do recommend going to this restaurant. That being said, call to place a reservation and make wise choices with your meals. If you want a run of the mill, simple dosa - this may not be your cup of tea.