For now, until I gather more information please enjoy these awesome " baggers " in action.
A look at the Art of the Speed Bag
This is amazing. The sound, the cadence, the power and definitely the speed. You may become mesmerized or addicted or both. You will meet people like G-Town, Speedy T and others. The most important figure will be Alan Kahn the undisputed Godfather of the Speed Bag.