When we arrived in Lisbon, we took a taxi from the airport to the apartment, and called the hosts and someone came to let us in within 15 minutes. He kindly showed us into the apartment, and gave us a quick rundown of the apartment rules, which were pretty standard.
We found the apartment to be comfortable, very clean, and our kids loved having their own rooms. There are three bathrooms, which seemed a bit excessive, but the kids thought it was fun to switch it up, so that's more an observation than a criticism :)
The location turned out to be amazing, as we could walk just about anywhere you'd want to go in Lisbon from our apartment within 20 minutes. The apartment is also close to several bus stops and tram stops, but we mostly just walked. I highly recommend the Time Out market and the Medieval Tavern if you stay here.
The one negative about our stay in this apartment was that it was robbed while we were out sightseeing on our last full day in Lisbon. There was no sign of a break-in, and the windows and door were fully locked when we left the apartment in the morning, so we suspect that someone had somehow gotten a copy of the key to the apartment. A few electronic items were stolen, and we had to go to the police to get a police report so we can hopefully recover something from our travel insurance. Our hosts were responsive when we told them what had happened, and helped us get in touch with the police, and I confirmed with them that they changed the locks after we left.
I would still recommend this apartment, even after our experience being robbed, because it is still a beautiful place to stay in a great location. I think my family learned, and I recommend to anyone staying in ANY Airbnb, to put valuables and electronics out of sight and to even slightly hide them when you are away from the apartment. This apartment particularly has ample, almost ridiculous amounts of storage space, some of it very hard to see into without using a ladder. If we had thought to be more careful about just leaving things out on the table when we were gone, perhaps nothing would have been taken.