Well, I believe that the diference between Brazil (PT-BR) and Portugal (PT-PT) is so similar US and UK, but we have a big difference in speech diction. For exemplo in english: When you say "unfortunately" you say "un-fortu-na-tely". This same word, if it was a portuguese word it will be say in PT-BR "un-for-tu-na-te-ly", but in PT-PT "un-fo-ntly".
The different forms of Portuguese around the world basicaly are 3: PT-BR, PT-PT and Galego (galego is similar a PT-BR + Spanish). Obviosly that PT-BR is only on Brazil (with more than 27 accents) and PT-PT is in Portugal, Angola, Mozambique, Guinea-Bissau, Cape Verde, Sao Tome and Principe, East Timor (each one with your various accents).
In the youtube I found a video of a Portuguese saying his experience in Brazil. He said that when he got here, he understood 90% what people saids, but the people understood 10% what he saids. After some days he realized that speaking slowly, it improoved by 50%.