Just finished my bachelors in Economics at NOVA and can say that my time there has been great.
You are surrounded by ambitious but very friendly students who are not only from Lisbon but also from regions all over the country. Moreover, at the BSc level, foreign students mostly come from Portuguese speaking countries, who experience a smooth integration process in the broad student environment.
In general, professors are well prepared for the classes and speak a frankly good English. On the other hand, practical teachers mostly consist of students pursuing a MSc at NOVA, who also teach good quality classes and are approachable and available both inside and outside the classroom.
Personal
Personally, I would like to highlight that NOVA is a very modern university, which offers the opportunity to meet other students with similar interests through dozens of student clubs, while, at the same time, it is open for the local community (NOVA certainly is one of the favourite study points in the broader Lisbon area) and for internationals (Germans, Italians, Brazilians and so on) because of its prestigious masters programmes and beautiful location close to the beach.
On the other hand, even though student life is quite vibrant at NOVA with sunsets and parties organized every now and then by a numerous and seemingly well funded students union, and activities, case challenges and conferences co-organized by student clubs, I think that Carcavelos is a bit boring (other than the beach and NOVA, it is a calm place to live) and falls short in terms of academic tradition and post class activities compared to other colleges located in the centre of Lisbon. Furthermore, the traffic becomes a problem in rush hours and public transportation usually takes longer than 40 minutes to go either to Lisbon or Cascais. The Carcavelos area is described as expensive for accommodation and hard to find single bedrooms, with prices usually above 500 euros in a shared house.
Lastly, I greatly recommend you to apply if you are interested and expect a lot of sun, but also quite windy days!