We had an excellent experience at Guido's place. Not only was he available during a late night check-in, but helped us with great tips and recommendations throughout.
The place is very well located. Walking distance up the hill to the Citta Alta and equally close to the Citta Bassa. Guido was also able to offer a couple of additional services at minimal additional charge, such as a secure parking spot for our rental car.
The place is very well suited for groups of 4 and could even accommodate 6 with the sofa bed in the living/dining area. We were very happy all around and if we ever return to Bergamo, we will certainly stay at Guido's again.