Overall, I am very pleased with this machine and I highly recommend it, but there are some details I noted further in this review that you may be interested in.I bought this for its variable speed option. I use it for buffing instead of grinding. Buffing should be done at about 1500rpm instead of 3400rpm. The lower buffing speed helps the material from becoming overheated. Even though this grinder runs at a minimum of 2000rpm, it is still much better than buffing at 3400rpm.I posted some photos as reference to what I am talking about in this review.Adjustable speed:The dial for adjusting speed is located on the front to the right of the power switch. It is a durable dial and feels like it is mounted well. You can adjust speed from 2000rpm to 3300rpm. Then there is a click at the highest setting that jumps the speed up to a max of 3450prm. It does not take long for the speed to adjust, and you can kind of tell when the processor it regulating to the correct speed. The processor is located within the base of the machine.Power at different speeds:I tested several different parts and pressures to see if the torque was reduced at lower speeds. I did not notice any difference in the power that it gave. It held a good amount of torque at any speed and seemed to be a little stronger than my Black and Decker grinder that I also converted to a buffer; even though both have the same horse power rating.Power switch:It works well, but its mounting is weak. It almost feels like it will pop out of the machine. It hasn't yet.Vibration:There is some vibration, but it is minimal for a machine in this price category. Vibration is a tricky thing since the grinding wheels can cause more vibration than a machine does. When I tested this Palmgren machine with the grinding wheels on, it had about the same vibration as my Black & Decker grinder, but less than my old (1970s model) Craftsman grinder. With the grinding wheels off, it had some vibration, but it was evident the wheels were causing most of the vibration.Grinding wheel manufacturers aren't the best at balancing their wheels. Therefore, if you get a machine that has lots of vibration, try changing the wheels to see of that helps.Stability:This machine is fantastically stable and has a wider base than my other grinders. When not mounted to a table or stand, my other grinding machines vibrate all over the place and cannot be used until they are mounted. However, I tried this machine not mounted and it stayed in place. I don't recommend using the machine not mounted, but I just wanted point out how well the base is designed.Wheel housings:The housings that go around the grinding wheels are very durable and well built; much better than other grinders (within this price point) I have used. The vacuum attachments are placed in a good position to keep the machine functional and suck up most of the debris.Resting platforms and guards:The resting platforms are thick metal and have secure mounting. They are also a good large size instead of being small like on other grinders. My other grinders have cheap and thin platforms that move too easily and bend with little effort. The eye shields of this Palmgren are ok; they are the same as my Black & Decker grinder. This means they are good for a home shop, but not what I consider to be good enough for an industrial shop.Motor housing:What I really like about this machine design is that the motor housing is long and narrow rather than fat. The large diameter motor housings get in the way of grinding or buffing large items, but this Palmgren housing is small enough to allow for grinding large items without bumping the motor.Wheel washers:If you note in one of the photos I posted, each side of the grinder has different types of washers which hold the wheels. The coarse side as the large, thick washers; and the fine grit side has the normal grinder washers. I don’t know what the benefit this design is, but I just wanted to note it for your reference in case you are using this machine for other purposes like I am.So far, this machine has performed very well for me. I will probably get another one to replace the junky, vibrating Craftsman grinder I currently have.