Overall: Enjoyed our stay. The location of the apartment is the biggest plus, as it is just a <10 minute walk from La Boqueria or Las Ramblas. It's also on a street that has plenty of food and just a short few minute walk away from a street full of bars. Because of this location, it does get a little loud at night so for those who are bothered by noise, this may not be for you. However, the host is very accommodating and will walk you through the check-in process as well as give you a short tour of the apartment as well as its amenities.
The pictures of the listing make it appear much larger than it actually is. My group of four was a little crammed into the apartment. I don't think the apartment was designed for four people (i.e. the last person taking a shower would take a half-cold shower). It gets quite stuffy. As for amenities: We booked for an entire week and were given two rolls of toilet paper and a couple of hotel-sized shampoo bottles and bar soap, so naturally we did make a trip to the market to purchase more. Additionally, it's on the third floor (third meaning five flights of stairs -- fair warning), which is quite a walk up steep stairs. The good news is that the washer and dryer units are just two floors above!