Review on ELECOM 8-Button Finger-Operated Trackball Mouse: Wired/Wireless/Bluetooth, Smooth Tracking & Precision Sensor (M-DPT1MRXBK) by Steven Ross

Ball motion is especially sticky when moving at certain angles. I think they made a serious design mistake by placing small support balls. They don't land the ball on a plane parallel to the table surface. This allows the ball to detach from the supports when kicked from the side. The support spheres are also too close to the center (equator, if you will) of the sphere. I think they would do better if they were a little closer to the South Pole and supported the ball from below. The ball seems to stick. Not sure if it's rubbing against the body or bad friction between the support ball and the main ball. Compared to my seasoned Kensington mouse, this is a real disappointment. The buttons are amazing. More buttons than I need. The key placement is excellent. I'm using a device on Linux and I manually remapped the buttons (ButtonMapping is set to 1 12 2 4 5 6 7 9 8 10 3 11). There's also an additional normal button and a mouse wheel button (which is a bit difficult to press without moving the wheel and activating the side scroll button). It's pretty good ergonomically. I wish the ball could sit a little further forward. I find it difficult to get good ball control when my palm is pressed against the device. It comes in handy when my palm gets stuck, so it's not really a problem. I like the many connectivity options, but I couldn't pair Bluetooth with my Linux desktop (worked great on an Android device). Processing quality is ok. Feels a little light/cheap in the hand but feels solid on the table. 1 month update: This replaced my veteran Kensington mouse. The ball movement is still interrupted. Trying to make small tweaks from the spot always results in the cursor jumping more than I'd like. In my actual use (general computer, gaming) this doesn't cause much of a problem. The ball sometimes makes noise through small debris. It is difficult to clean because the source of the problem is not visible. I end up brushing it two or three times to silence it. I initially liked the textured surface, but it picks up dirt easily.