Mr. Nagata took care of my family during three days (two in Kyoto and one in Nara). His vehicle is impecable (Toyota Van for six passengers).
He is very knowlegeable, knows very well the city and the sights.
Three days may seem like a lot of time in Kyoto. You can be there for a month. There is no way that we would have covered as much as we did without Nobu´s help.
I strongly suggest any traveler to Kyoto to use a private service.
You will waste a LOT of time moving from one place to another. You have already made the expenditure to be there. Do not waste time walking or waiting for the bus.
Spend that time visiting the sights.