Our family of 4 stayed 8 nights in late November, and we love this apartment/hotel. Friendly staff, clean and well maintained rooms, secure, close to metro and to the deservedly famous Sagrada Familia, great grocery market just around the corner, cafes and good restaurants short walks away, and a very fine restaurant (La Cupula) attached to the hotel.
Minor complaints: our room overlooked a busy street and traffic noise lasted well into the night. The windows are pretty thick and good at shutting out most of the noise, and we slept well overall. Ask for a room on a higher floor so you have a view from the cute balcony.
The kitchen could use more cooking equipment, so if you plan to cook in a lot bring along a good knife and frying pan. Otherwise, the kitchen was adequate. The washer/dryer was weak by US standards, but serviceable. Dishwasher OK. Take along some detergents, a sponge, paper towels, salt/pepper, sugar, tea bags, if you can fit it in. The coffee maker is a Delonghi pod espresso type, so ground coffee is useless. Buy pods.
More positives: we ate twice at La Cupula and loved it both times. My teenage sons still talk about the meals we had there. It's a bit pricey, but it is a Michelin rated place and the hotel gives you a 10% discount. They also have a fixed price menu that changes daily for a reasonable 13 or 14 euro (19 dollars), and the wine list is very reasonably priced. The paella we had at La Cupula was by far the best version of several we tried that week.
We would definitely stay there again. And don't let all the chatter about thieves and pickpockets deter you from visiting this fabulous city. Just use common sense. Lock your passports and other valuables in the room safe, hide your money and credit card inside a zippered pocket, avoid La Rambla at night, and enjoy! We never felt unsafe all week. The people were the friendliest of any city in my experience. No one gave us "attitude", even with our very limited ability to speak the language. At our last meal (Maitea Taberna) the server presented us with the bill and a complementary bottle of Rioja! When has that happened to you in the U.S.?