This is a great apartment in many, many ways but there were a few things not so great:

Advantages:
A few minutes walk to the metro (Janic) and a few more to the Sagrado Familia
Nice patio although the sun only hits it in the afternoon
Fairly spacious, as least for two people
Great to have a washing machine and dryer if you're staying for more than a couple of days
Good local shops for food and some great local bars tucked away
Quiet neighbourhood
Flexible check in/out times

Disadvantages:
Thin walls so can hear the neighbours, got woken up by noise a couple of times
The smaller bedroom has no windows (which some may love)
The beds aren't that comfy (but that may just have been me as I have a back injury)

Overall, I'd really recommend this place to stay. The owners (a private company) were mostly good at getting back to me before I left and the one time I contacted them during our stay they got back to me immediately and offered assistance.