I understand Estrela, but I don´t think it really a matter of opinions. There almost identical. Of course tranmontano enthusiasts like to say they´re completly different, but I think If you look at them you´ll find it very hard to spot big differences. Transmontanos are quite possibly alentejo mastiffs that became isolated in the region of Trás-os-Montes(were they come from) and with time they became bigger and developing some carachteristics of their own, since Trás-os-Montes is a mountain region with a much more agressive climate, as oposed to Alentejo region that is hoter a mostly made of plains. :D