I think that less the 3 stars is a bit harsh.
Nando's chicken is either good or excellent, depending on your preferences. Some of my friends love it and swear by it. I don't, but I still think it's 1000x better than swiss chalet.
If you are craving chicken, then come here and order chicken. If you order only chicken, you will be satisfied. Don't forget to add sauce. It's an essential part of the experience.
However, there isn't much else to offer. The sides are expensive and underwhelming.
Furthermore, the restaurant is sometimes filled with tables of dirty plates. Plus, you are basically serving yourself.
It can also take longer to get your food than it should.
Stick to the chicken.