This is my first time in Yerevan, but not the first time in hostels and guest houses. And I'm putting a 5 on this place. It's clean, cozy, and the staff is caring. Breakfast is served in the morning, don't oversleep. There is a shared kitchen and a living/dining room, a patio. They say it's very green in summer, but I was in March, I'll take your word for it. The establishment is located in a rather pleasant part of Yerevan, very close to bus stops, shops and cafes, and you will have to walk to the metro. Tours are also organized here, you can get into the company with other vacationers, you can book at least one.
In general, I plan to visit Yerevan and stay here. Snorkel!