We stayed at Carlos's apartment for a week, and overall really enjoyed our time there. The place has windows in every direction, with a lot of sunshine. It's also very clean and spacious. The neighborhood is very peaceful -- except for the neighbor's little dogs which did some barking during the day, but never late at night.
There were a few minor things which could be improved upon, but Carlos responded to our requests kindly and promptly. He also gave helpful restaurant recommendations.
If you are looking for a peaceful, quiet, modern apartment in Estoril, and you're ok being up the hill a bit, then you might like this unit a lot.