Keep in mind the new Brittania woofer is front mounted. Like all speakers with front mounted woofers, using spike WILL improve the coupling of speaker to the floor and prevent the drivers from shaking the whole box and smear the sound. Subwoofers are less sensitive to time and image smear, but you will still gain pitch and speed by rigidly couple the sub to the floor.
Old ST series do not benefit from spikes, but that is NOT true with the new B series.
Old ST series do not benefit from spikes, but that is NOT true with the new B series.