This was a great place for 5 adults! The location is perfect, very walkable (keep in mind that Lisbon does have hills). Lots to do around the apartment itself and an many places for dine in. There's even a tour company shop down the road. And the grocery store was also just up the hill.
When we arrived, we bought a sim card at the airport to call the company. It was a very easy check in and we were lucky to get an early check in. I think the communication prior to our arrival was a little automated rather than personal. But it all worked out okay.
The apartment itself was nice, clean, and modern. Lots of natural light. All the appliances were functional (except the upstairs TV). They provided the kitchen basics if you wanted to stay in for meals. They also provide you with a local cell phone which was very useful. The apartment is also on the 4th floor but there is an available elevator (it is small for 2-3 people only at a time). But after the great food in the surrounding area, we didn't mind the walk upstairs.
I think the only downside for us was the smell in the upstairs bathroom.
All together a great experience.