João's apartment was perfect for a group of 8 for two nights, we were within walking distance of everything we were keen to see in Lisbon and there was even a bottle of port waiting for us upon arrival!
The apartment was a generous size and well decorated, however I could see it being a very tight fit for 16 people! The rest of the building appeared to be similar airbnb type apartments (so no obvious permanent residents), so there were times when the building was quite noisy (particularly people crashing up and down the stairs after nights out, and general noise from the apartments upstairs) however it was nothing earplugs couldn't drown out.
We were very pleased though, and I would definitely recommend for 8 people staying for a few days. We had a lovely stay.