Pros: Ergonomics. Fits snugly, as if the hand were a glove. The volume of the button presses is little higher than ideal. There is a backlash when pressing the DPI button. I appreciated that there were no flimsy locks on the magnets' lid. Ill effects: The receiver is only 20 cm distant, thus the cursor maintains its position in the line of sight. The slide was not to my liking. The mouse has a small right-to-left sway when placed on a hard, flat surface. Poor adhesion prevents the slide strips from staying in place; dust accumulates on the adhesive around the edges of the stickers, and I had to use a hair drier to nudge them into place. Although I purchased the mouse sealed and unopened, the back sticker shows signs of having been peeled off and reapplied at some point.