I've caught this service before (back in March) and it was again, utterly wedged. The driver was a rather formidable woman who looked to be in her early sixties and she was taking absolutely no prisoners with passengers nor with other traffic. I managed to nab the front seat so had quite the view of everything.
Still, not as bad as the Porto Airport bus I caught last year. The driver steered with his knees while he sent WhatsApp voicenotes at 40mph down residential streets. Still, he clawed back our delay, and then some.
Love it!