We spent 16 nights at the apartment and would totally recommend it. It is beautiful, spotlessly clean and has everything you need. We worked for half of that time and the internet connection was brilliant, by the way.
You are going to hear and see planes at all times of the day. We moved to the inner room so it was ok but bear this in mind. I wouldn't pass on the apartment but would bring some earplugs if you are a light sleeper.
But honestly, try it, the flat and customer service were perfect. Thinking of trying their property in Campo de Ourique next time - we went there a few times and loved the area (super close to Campolide so definitely go).