(useless rant) Most "baristas" will never touch a bottomless portafilter in their entire career for one simple reason. It is ruthlessly unforgivable. Bad techniques will results in the espresso squirting all over the place (and of course, a horrible taste in your mouth, if you dare to take a sip). But when good techniques come together with fresh beans, the portafilter is a barista's best friend.
Even to untrained eyes, a good espresso pull is something. (/useless rant)