I will write a detailed review, but mention firstly that this is a 5* place for us. I will point out some small things in the interest of a full review, but by no means did they take away from the pleasure.
1. Booking, check-in, throughout our stay and check-out: the staff (and I mean a rotation of staff) were all excellent, responsive and full of information and help! You cannot get better communication and service, it was over WhatsApp so it was very convenient, no need to call at odd times or wait for emails etc.
2. Location - if I told you you could step off a bus or tram (758 and a couple more or 24E respectively) and into the apartment building front door, I will not be lying. The stop is called Elevador da Gloria. There is a cafe open early to late just next door literally for water, coffee and some basic stuff. It is bang opposite a "lookout" park that looks over much of the city and a castle in the distance. You could turn left or right outside the building and while the inclines are steep in one direction, there are enough things around to keep you interested. If you instead turn off the main road inside to the side roads, there are innumerable bars and small places which come alive at night. In short if you want to experience Lisbon in its full glory, you stay here. It is also next to the inclined railway station (its actually a tram) that goes down, we did not use it. The football stadium is nearby and the fans all mill around and sing at night in bars etc - adds to the atmosphere, though I get how some would find that loud - we did not. There is a small market that pops up opposite in the lookout park that is cute and has a few local things for sale to eat or buy. Area feels very safe and there is always a small police presence, in a non-threatening way due to stadium and bars being there. They are always milling around, so we felt safe at every hour we were out.
The apartment itself - the building is right on the street, narrow entryway using a code provided by owners. The lift is tiny - four people can stand next to each other, only if they are family or intimate with each other :-) and another code gets you into your apartment (one to a floor only). Inside it is beautifully decorated, thoughtfully stocked with anything you can think of that you could need. Fridge, freezer, washing machine, dishwasher, detergent, dishwashing soap, TV, one full double bed, two single beds, kettle, toaster, microwave, utensils, towels/linen - cupboard with more if you need, I could go on. Suffice to say, other than food and water, which you would get from outside, we needed nothing. It is small, as you would expect but unless you are a giant, everything is perfect for your stay. Bathroom and toilet is tiny but fully functional. The bathroom sink is the smallest I have ever seen. I have seen bigger ones in trains :-) But very thoughtfully provided with ear plugs, soap, shampoo + body wash etc etc. 10 out of 10.
In short, this place is HIGHLY recommended in every aspect. If we return to Lisbon, this is the place we will stay at, hopefully I haven't made it too popular by then with this review :-)