I recently acquired dual citizenship for an EU country (Portugal). I already have a US passport, so I was wondering if there is a major benefit in getting a Portuguese passport over just a Portuguese citizen card if my main goal is to freely travel Europe. Are there any notable benefits to having the second passport? From what I understand, I can present a national ID card when entering the EU from a non-EU country without needing a passport to skip the non-EU line. What about visas for other countries (eg. South America, Australia)? Is a Portuguese passport necessary to get visa-free travel to Brazil for example?
Also, if I wanted to live in Europe, would an EU passport be necessary or would the citizen card suffice?