I stayed four weeks in the ground floor apartment at Bela Vista Palace in Jan-Feb 2022. I was very happy with my stay and the apartment matches well its description. The apartment is clean and modern, recently refurbished, in a beautiful old villa/palace, with all the facilities you would expect, including very fast internet connection. It was winter and the apartment was very warm and comfortable - this was very important for me since I work a lot from 'home'. Warm apartments can be hard to find in Portugal in winter but this one has a modern heating/cooling ventilation system and was very comfortable.
Even though the apartment is located on the ground floor, it is very calm and quiet. The road is a small residential road with not much traffic or noise. There was also not much sounds from the other apartments.
Location of the apartment is excellent - it's very central. Within a few minutes you can walk to Cascais town center, the beaches, and the coastal walks. If you like walking, there are excellent walking routes either along the coast or north along Trilho das Vinhas (nice walk in the woods along a small river valley).
There are some supermarkets within an easy walk and plenty of other shopping too.
I had my car with me and I used it nearly daily. It was relatively easy to find a parking spot (for free) at Mobi Cascais indoor parking hall only about 200 meters away from the apartment.
All in all I'm very happy with my stay and can highly recommend Bela Vista Palace Apartments. Vasco's team was super fast to reply to my inquiries. They are very friendly and everything was always handled very professionally.