The apartment is extremely centrally located, literally around the corner from the Opera house. The apartment itself is very modern, and very clean. The bathroom and kitchen had all the amenities you could ask for - tons of space and a beautiful balcony. There is a guard at the front of the building and the area in general seemed very safe.
Things to note: you have to get in touch with the manager via phone to get the key, which can be a bit of a hastle. (otherwise you can email the manager your exact time of arrival so that someone can give you the key). Payment is required in cash upon arrival (they don't accept credit cards) in the office right next door to the apartment building. Towels are provided, but you have to bring your own soap and shampoo and ofcourse, there is no breakfast. Management was easy to deal with though, spoke good English, and was very helpful regarding sight seeing around the city.
If you need to have a front desk available to you at all times - then this isn't the place for you. I found that with a guide book and talking to different strangers, I was able to gather enough information to get a handle on the city though.
Overall - a great value, lots of space, beautiful apartment. I would definitely stay here again if I returned to Budapest.