The apartments are in a great location, we arrived on the train and it was a 10 minute walk from Sants station, the metro was 30 seconds away (and was very easy to use, including to go to the airport) there are lots of restaurants and shops nearby.
check in and check out was very easy, there are staff on site 10am to 7pm every day. Our train was delayed but I just called and let them know and it wasn't a problem at all.
The apartment had everything you might need however we did find that a lot of the things in the kitchen hadn't been cleaned properly, the balcony furniture was sticky and the bathroom hadn't been properly cleaned.
There is a lovely roof terrace with seating, sunbeds, sofas etc though we didn't use this.
Generally we were really happy with our stay.