This apartment will work for you if you plan on visiting the city most of the day. It's small and dark. The kitchen is well stocked and the bathroom is spacious. The apartment is a few blocks from the historic Mercat de Sant Antoni.
The lack of washing machine makes doing laundry logistically difficult, though there are laundry mats nearby. There were a few details that made staying there with children slightly uncomfortable: the unfitted sheets came off the bed constantly, the shower doors were difficult to close, the shower head didn't fit on the holder and had to be held by hand so the bathroom floor got soaked, the edge of the heater came off and was hanging on by wires. If these issues were remedied it would be much more comfortable.