The other reviews have pretty much nailed it -
1) Location is amazing as it is close to many restaurants, bars, shopping. Many free walking tours start just around the corner at Praca Luis de Canoes so you can get to know the city quickly. I was able to walk to Alfama and Principe Real, and go to Time Out Marker for dinner twice
2) We stayed Monday through Thursday and there was partying all nights of the week as others have mentioned. I recommend ear plugs!
3) The apartment staircase is narrow, but once you are upstairs it will feel spacious in the living room. There’s a designated table for eating and a full kitchen so you can cook if you wanted to. I liked the floor to ceiling window and balcony.