This is my second time to stay at Rachid's place and can't say enough great things. It's large and comfortable and very well equipped. Everything works really well and love the oversized shower with waterfall shower head, and a desk that's big enough to actually do some work if you need to get something done while you're in Barcelona. There's also an amazing amount of storage and closet space if you want to fully unpack your suitcase and live like a local for a few days.
The location is great, with lots and lots of restaurants and shops just outside the front door - and the old town or harbor are just a short walk away. And while you're close to the lots of action, the apartment is removed enough from the street that it's quiet even when the bars and restaurants are very busy.
The only caution is that the building doesn't have an elevator and the apartment is on an upper floor. If you have a problem with stairs I wouldn't recommend it. Otherwise it's a great place as a base to explore all of Barcelona, and to be very comfortable when it's time to relax and unwind.