For the most part this place is exactly how it is presented. It is close to Park Guell and another park but is far from most of the other attractions in the city. It would be fine but Barcelona is hard to get a cab and they don't have Uber. They do have a uber like app called cabify, but it is not as well established as uber is on most cities. There are 2 bus stops very near the apartment which takes you almost everywhere. I guess the best way to put it is if it is your very first time in Barcelona, you might try something more central.
The apartment itself is small but plenty of space for 3 people. It is mostly clean but there were a few minor things that would have made things a lot more comfortable. The other thing is that there are a lot of steep stairs. The first set leading to the apartment, can be slippery if it is raining. I fell down about 8-10 steps. If you are elderly or have small children I would think about staying somewhere more central.