This Greece tour operator handles travel very well. I had no problems with scheduling or pickups, and a representative met me at the hotel on the first day to go over the itinerary, local special events that might be of interest, and personal contact information in case there were any problems.
The day trip to Delphi was so much better than I had hoped for it to be. The view from the Temple over the mountain valley is spectacular!
I would stay longer. At least two days just to wander around Athens and see the city without a tour.