I'm using four of these subs. They are very light and easy to move (Have them wheeled, was so light I did debate not wheeling them at all) Great sound. The rubber feet hold well when stacking the speakers and even a high volumes do not slip at all.
These bins sound awesome. Loads of thump off them and very defined and clear bass. My only negative things to say are that the wood is quite thin especially at the bottom of the bins where they are prone to the most knocks but this is also why they are so light. The handles are plastic but fairly solid feeling and hopefully will last, and there is no crossover switch on the back to allow for bi-amped wiringm which means you will need to make a crossover cable if you wire them bi-amped like I do, but overall superb sound off these and I would definately buy more of them.