On Google Maps (at the time we visited) the outside of the apartment looks a little unappealing; there's a small convenience store right next to it and the building opposite is in a very bad state. However on going inside it's like you're in a different place.
The apartment is bright, comfortable, airy and (mostly) well equipped.
In the master bedroom there is plenty of storage and a comfortable double bed. The 2nd bedroom has 2 single beds (one of which can be stored under the other) and a large built-in wardrobe. It's not a massive room, but there are two large sofas in the lounge, one of which is a sofa-bed, so that can be used if you want a bit more room for 4. The lounge also has a dining table, and a good sized TV, coffee table and storage.
The bathroom is a good size, with toilet, bidet, double sinks and a bath with a fixed and flexible shower head over it. We had some slight issues with the shower as it's run off a combination boiler so, occasionally, would just go cold and you'd have to wait for it to heat up again. As the gas comes from a canister under the boiler, I did wonder if we were getting low on gas, but that was on the morning of our last day so I didn't check!
The bathroom, however, is the only room in the apartment that, during our visit, had a mirror in it so the women/girls who wanted to put make up on, or dry their hair etc, had to wait when someone had to use the toilet for other purposes!
The kitchen has a washing machine, dishwasher, hob, microwave oven, fridge, filter coffee machine and breakfast table in it so has everything you would need really for your break.
The apartment is only a few minutes walk from the Cathedral and the Real Alcazar and just round the corner from the main shopping streets. For visiting the sites of Seville it's hard to imagine a better location; we visited loads of different tourist venues and none of them were more than around 20 minutes walk away. There are also loads of places to eat within just a few minutes' walk.
However, there are a couple of pub/clubs nearby that generate a lot of noise, and this is a bit intrusive, particularly on the Friday night that we were there, when the noise continued until well into 5:00am. There's also a surprising amount of traffic in the street that also causes noise in the mornings.
As other reviewers have said, it is worth taking ear-plugs with you if you're staying here as the double-glazing doesn't insulate against the noise much, even with the external shutters down.
Overall though, we enjoyed out stay here. Carmen, who met us to check us in, was extremely helpful in telling us good places to go to visit and to eat, and responded quickly to any questions we had during our stay.