We fell in love with Lisboa in our (much too short!) 3 day holiday, and Manuel's flat set the tone from our first moments in the city. Manuel was an incredibly accommodating host, and has spared no expense on the refurbishment and design of his top floor flat. If you like spaces that have a very specific design perspective - you'll love this!
The location is great in that it's not right in the middle of the chaos of the Barrio Alto or Chiado districts, so it's much quieter at night and in the mornings, and is < 10 minute walk from these destination neighborhoods. The lift was consistent and made being on the top floor a breeze (though there is a quick 6 or 7 step climb coming out of the elevator). The extra 1/2 bath was convenient and the small but well appointed second bedroom with twin beds gave my partner and I son extra space to spread out into! It's worth noting for summer travelers that the AC works great!
The only considerations you should make for your travel situation are in regards to privacy of the shower and the bed size in the master. If you're traveling as two couples or bringing kids, there is no privacy between the master bedroom and bathroom (where the shower is located). The master bed is very comfy and is a full mattress, so long people might find it a bit small.
As a mid30s couple traveling alone and who have not been particularly blessed in the height department, it was perfect for us!! :)