We really wanted to get a good feeling for St. Petersburg and did we ever get it with Best Guides! Andrey and Masha worked with us to put together a very specific tour for me and my family with maximum flexibility and quoted us a very fair price all-in.
But things got better when we met our guide, Inna. She spoke amazing English and is a really warm, caring woman who was very proud of her city. Over the course of 3 days, she took us to the see the sights (e.g. the Hermitage and Peter and Paul Fortress), but also showed us things a little off the beaten track. We learned about her family and a little about how the citizens of St. Petersburg live.
And aside from how well they took care of us, Andrey was incredibly honest, which shouldn't surprise me, but still did. The last day, we felt like just hanging around the hotel for an extra hour, so we started the day late. Andrey wrote to me, telling me he had adjusted the price down to reflect the hour we did not use.
So to summarize: 1) excellent communication and flexibility, 2) great guide, 3) very reasonable price, and 4) honest.
And by the way, did I mention that St. Petersburg is a magnificent city?