Our stay was fantastic. We were a large group, 6 (but was supposed to be 7). First off, the beds were all made up as we needed before we arrived. The kids room was made up as two beds instead of one. And, they didn't realize that our 7th couldn't come so they had even made up the sofa into a bed before we arrived (I love that detail, usually I have to do it). There was plenty of space for everyone. The dining room had seats for 6 and a stool if you have a 7th. The kitchen has what you need for quick meals, a washer, and a huge clothing drying rack.
A few things to note. This is a European washer - aka small. We had to do multiple loads to get the weeks' worth of laundry for 6 done. However, it does a great job of wringing out the clothing. If you put it on the rack, they are dry really quickly, even think pants and jeans.
If you are tall, the walk in closet / vanity room in the bedroom to the right of the door has really short ceilings. I am 5'5" and I could stand up. My 6'0" husband bumped his head more than once.
The AC cools down the shared areas, but not as much the bedrooms. However each bedroom has an oscillating fan. That with the windows cracked open at night made it really comfortable.
The location can NOT be beat. You are by several tram and bus lines, and the area is all flat. There are so many good restaurants and your walking distance from 80% of the major sites (assuming you don't mine walking uphill).
The hosts are amazing! They offer so much communication. They set up a WhatsApp Group and always responded quickly. They helped us arrange private airport transfers both on the incoming and outgoing since our flights were at odd times. And they helped with any questions/issues we had.
If you have a big group, this is the place to stay in Lisbon.