I think the La Musica is the only volumetric in your list - is that required?
Its not all about looks, some are definitely better than others with pipe diameter, pressurestats, etc, but I cant rattle off the exact differences. Have you visited Jetblack in Adelaide? It really is worth viewing and playing with the machines "in the flesh". Someone like Jetblack should be able to tell you more specifics about each. Otherwise TalkCoffee is very good at machine comparisons if you want t do that remotely.