Sela is a wonderful host, very responsive and communicative. The apartment is in an excellent location as well! The Gràcia neighborhood is great for visitors who want to enjoy the shopping, restaurants, and cafés that Barcelona has to offer without being stuck in tourist central. :)
The apartment itself is a bit quirky but great value for the price. The elevator and air conditioning are truly welcome (most Barcelona apartments lack them). The only drawback/heads up is that the toilet is separate from the rest of the bathroom and is in an extremely small space, such that you basically have to leave the door open. Not a dealbreaker at all though, because this apartment, location, and host are all wonderful.