While the Avel guest house is a decent trip from the heart of Sofia (don't walk, and don't let the taxi drivers swindle you--it shouldn't be more than 7 leva, but I was charged 25), the distance is really more than made up for by the hospitality and helpfulness of the staff. Jordan, who I believe runs Avel now, brought me a map, made me some tea, explained his favorite sites, and taught me a little Bulgarian and would have helped me more and more if I'd asked, I'm sure of it. He was really a model of hotel service and for him alone I would recommend Avel. That, and the very reasonable price.