I am huge Bob Warzalla fan (Sound Anchors) and they were required equipment with old 801/802 as well as Nautilus up to 803 series (I sold B&W for 6 years through Nautilus roll out).But Rhljazz might have point.Newer 802/801's need them less.Yet extra mas under speakers never hurts with wood floors.I might try paving stones first to minimize rise as rule of thumbs you want tweeter directly on axis with your ears as I am sure you know.Will a local dealer give you trial???
Cheers
Chazz
Cheers
Chazz