First of all the Brasilia bottomless fits all known models. Include the Century, Brasilia Portofino, Majore. Moreover the portafilter fits the Rito, Sofia and Excelsior models. It does not fit the Gradisca.
The Brasilia bottomless is purpose made in the factory. Most important is the edges are not sharp. It’s not a cut down version consequently the edges are smooth.
The Portafilter can use a double or a treble filter basket. It is possible to swap from one to another easily. Because the coffee meets less metal the crema is thicker. Crema is oil extracted from the ground coffee beans. Thus it turns brown when heated. It also floats sitting above the coffee in the cup.
Besides that baristas show class and experience. When using a bottomless the tamp has to be straight, therefore experience shows through. The best baristas use Brasilia bottomless portafilters.