Dennis, As a cabinetmaker I have had experience with quite a few sanders, several of them R.O. I've only used one dual speed, a Bosch that is too slow for general use on its low speed and vibrates too much on high. I've used a Craftsman that I thought was practically useless though in all fairness it was old and abused. I've used a cheap, variable-speed pneumatic that is great for rough, aggressive work though even on low speed it is somewhat difficult to control. I own a Porter-Cable that would be OK if the dust collector did not rotate independent of the body--this means you can't grasp the sander by to top of the motor casing. I also own a Skil right-angle R.O. Like the pneumatic it is coarse, aggressive and hard to control. I think they just added a R.O. head to a four inch grinder body. I also have a DeWalt without dust control and have used the same with dust control. At about $70 this sander is far and away my weapon of choice. I also have a DW 1/4-sheet sander that would be my choice when more control is desired instead of any dual- or variable-speed sander I have used. Unfortunately the shape of 1/4-sheet sanders is not conducive to concave curves. Good hunting, Tom