I and my wife stayed at the Buono Core guesthouse 4 days in March 2022. It was our second visit to Italy.
The location is great. It is about 13-15 min walking from the Central Station. We never used public transport. At the same time, the feeling is that we are far away from the noisy streets and even from civilization because we can enjoy the silence outside.
Ettore is the most hospitable and friendly host we have ever met. He gave us a perfect introduction to the guest house and Bergamo city.
Our room was nice. Especially, the shower room was very modern and of good quality. The kitchen has everything that we may need, especially, the coffee machine.
These apartments have a small nice garden where we spent time in the evenings.
We asked for some advice about restaurants that local people love. Ettore was so kind and he recommend some places. The food was excellent and the price was lower than in typical "tourist restaurants". We were here: (1) Circolino Città Alta and (2) Trattoria D'Ambrosio Da Giuliana. Highly recommend it to everyone.
There are two good supermarkets (PAM) and a couple of nice parks (Parco Suardi and Parco Marenzi) nearby the guest house. The distance to the "upper town" (Citta Alta) is about 50-60 minutes slowly walking by foot. Ettore gave us the unique city map prepared by him and his friends. It looks better and easier to use than typical official city maps.
During our stay, we spent two days enjoying Bergamo, one day visiting the beautiful Lake Como, and one day exploring the city of Brescia. Both Como and Brescia are easily accessible by train (40-60 min one way).

Dear Ettore, many thanks for your warm hospitality and care for us during our stay in Bergamo.
Sincerely,
Alexander and Alla