Good small apt for two people! 3+ would be too much unless they can sleep on a small couch.
Location is close to public transportation, food, drinks, attractions, and lookout points. At night when you look out the balcony, there will be dancning, eating and drinking everywhere with lot's of music. Once you close the doors though, it becomes super quiet, allowing for a good sleep.
Alfama district is a lot cooler and entertaining than anywhere else in Lisbon in my opinion so this apt was perfect.
You will be close to the water, but NOT to the beach so keep this in mind. If you plan on doing multiple beach days, you will need to Uber which for us was about 30 euros just to get there (Carcavelos). Public transportation will be a mix of subway and bus and take over an hour (not worth it imo).
Someone is always available if you have any questions or concerns and super friendly.
Shower is very small, just enough room to stand in it. You can accidently burn yourself on the hot water by moving too much and hitting the handle.
If you plan on renting a car, I hope you can drive manual very well...alfama streets are narrow, complicated and fast-paced for driving.
Overall- great apt and can't go wrong with it! Small and good for two people. Great location and host.
Just keep in mind the beach distance if that is part of your itinerary.