My friend and I stayed here last month, and were delighted to have found such a gem.
1) It's located in a leafy, peaceful district favoured by foreign embassies - and is just a few minutes walk from Alexander Nevsky Cathedral. Other key tourist attractions are about 15 minutes away by foot.
2) Forget what you might have read in other reviews; although this gorgeous little property is predominantly aimed at couples or single business travellers, it is possible to share a room with a friend. We enquired in advance and were given a beautifully decorated, immaculate suite - Tzarevetz - where the stylish, oversized sofa was converted into a second bed for us.
3) Breakfast is fantastic. Yes, you have to order the evening before, but this is only the slightest of inconveniences. In return, you can opt to have breakfast in your room (they don't apply room service charges here) or downstairs - both until very late in the morning. The portions are enormous, too. And there's a lot of choice. I can seriously recommend the Bulgarian breakfast.
4) The staff are incredibly friendly and helpful. They helped us sort out a little medical emergency without batting an eyelid, and were on-hand to deal with any requests we had - from sourcing a guide for a trip out of the city to answering questions about Sofia itself to providing free wifi passwords.
5) The on-site restaurant, Landau, was really well-priced - considering that it is a hotel restaurant. Both service and quality/menu options were great.
None. Seriously, you could nit-pick about little things, such as the fact that Residence Oborishte doesn't have a night porter or the fact that it doesn't offer a couple of rooms with twin beds. But these fade into insignificance when you compare them to what you get.
All in all, I would very much recommend Residence Oborishte - to couples, single travellers or small groups of friends.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.