Only the highest ratings.
Firstly, Giacomo organizes non-standard excursions to interesting places. Traveling with him, you'll make a lot of discoveries.
Secondly, he is very punctual and an amazing organizer: everything is done on time, but you don't feel any pressure and freely choose what and when to do.
Thirdly, he has an excellent manner of presentation, he knows a lot and tell interesting things (not basic information from the Internet (as some guides practicise).
Fourth, he is a great driver.
And finally, his Russian free and figurative, although it not native to him.