One its on pentelis 5, the other that's in the centre it's on st eirinis sq!
I visited the one on the sq and the souvlaki was very good and different from the classic souvlaki greeks eat. Instead of tzatziki he puts tomato sauce and if you like spicy pepper. The fries are fresh and the fresh tomato that goes in the pita is freshly cut right into your souvlaki.
It is a bit more expensive and a bit smaller than the average souvlaki in Athens (2,30 for a bigger one is the usual)
A very nice choice for Greeks too, who want to taste a different souvlaki.
I think it's only open untin 17.00 every day.