I stayed for four nights at hotel Cascais. It was truly up and down. First two nights were some of the worst as I was assigned a room on the bottom floor. Loud base from the neighboring nightclubs were going from 23 to 05ish. Additionally, my room did not have wifi coverage so I had to use the resurant wifi nearby, which was bad. There were no outlets that you could reach from the bed. After two nights I asked, and was granted to switch rooms. On the third floor I did not hear the disco music.
However, all throughout the hotel the doors have a gap which means you hear EVERYTHING. People are slamming the doors, talking, and not showing concern for others. Which means in any case you will not have a quiet stay. Also, at breakfast it can be quite crowded.
The main positives are it's central location and the fact that the room was clean and beds comfortable.
I would recommend staying further away from the clubs though!