We spend New Year's Eve in Lisbon so keep in mind we didn't spend too much time in the property except for sleeping and relaxing a bit before going out to see the sights or get a few drinks.
The apartment was fantastic: Spotless clean, LOTS of space, two bathrooms with hot water, a massive TV (I personally haven't owned one for years but we watched a movie on Netflix one night which was great fun), a nice kitchen (we didn't cook but the dishwasher was very handy) and a general location that is close to everything: The city center, places to have breakfast (make sure you go uphill and turn on the right, you'll see a great place on your right hand), lunch and dinner.
If I find myself in Lisbon with a big group again, this is definitely the first listing I am checking.