This hostel is in an old (130 years) house in a lovely and central part of Sofia. It's on a quiet street next to an excellent art shop.
The people working in the hostel speak decent english and you can book rooms over the phone (which we didn't find with Hostel Mostel).
We shared a twin room with ensuite bathroom with a towel included for 60 lev (30 euros) which included coffee and pastry for breakfast, which we ate on the balcony/terrace. Everything seemed clean. The common room was quiet when we were there in the middle of August. It has a television and some books.
Overall an excellent hostel which is good value for money. I would certainly stay again. more