hi i don´t have none of those breeds, i feel that even here portuguese breeds aren´t talked about has much has other breeds. i´m portuguese so i have experience with some of those breeds, i´ve talked to some cops that use Filas de S.Miguel in their job and they all tell me that they are pretty intense and agressive, and that it´s very dificult for them to accept diferent handlers. has my personal experience with them what i know about filas is that they are very inteligent, learn quickly, very atached to owner and great guardians. they are pretty agile and dispite the smaller size compared to other guardian breeds they make up with spirit :) if i would need a personal guardian the Fila would be on my top list. about the Serra da Estrela it has the typical temperament of a sheperd dog a bit more sociable, more watchfull during the night, better with other dogs and animals. don´t have much experience about the other breeds. about the portuguese breeds not being too divulgued abroad is because here we have the kind of mentality, were all that is from other countries is better than what we got, so our breeds are not so apreciated, because everybody want a rottweiler or a german sheperd, i guess all starts there.... hope i helped a ltle bit ;)