The first thing most folks ask is “Why do you have two styles of swivel bases?” The best correlation I came up with is a comparison to the wheels on your car. You have the fully functional rims that the car came with, but you also have the option of upgrading to nicer fancier wheels. If you decide to take the option, it will of course cost more. It is the same with these swivel bases. The next question is, “What’s the difference between the two?” The standard bases cost less, so are by necessity a cheaper constuct. The Premium bases are a much higher quality and because they are larger, offer a bigger footprint thus providing superior stability. The last question is, “Why not just sell your susans with the premiun bases to begin with?” Again, cost is the main issue. To keep the cost to you lower, the susans arrive with the standard bases. Not every one objects to the inherent noise level of the lower cost bases.