Two Manufacturers, Three Sensors
The protagonists, Microsoft and Logitech, currently use three different systems in their ranges. One for Microsoft and two for Logitech. The most technologically advanced and most precise is the Logitech MX. With its huge 30x30-pixel CMOS sensor, the surface shot is excellent. Then the resolution of 800 cpi ensures greater precision at a high resolution of 1280 or more. And last, a rate of 5250 images per second will meet all response requirements. As you'll have guessed, it is the ideal sensor for gamers and graphics designers (retouching, CAD, etc.). Logitech also uses its regular sensor, which is below 20x20 and runs at 2000 images per second, still at a resolution of 800 cpi. This reasonable combination gives good results and you have to be a really fast Quaker or a very sensitive touch to notice the difference between it and the MX. Though it's true you do begin to notice it after using it for a while.
Microsoft has once again deployed its classic, 6,000 image-per-second sensor, which only offers a resolution of 400 cpi. However, there is no difference in precision compared to the basic Logitech sensor. It is only in high resolutions, at equal settings, that the Logitech mouse is slightly faster and more direct. For this level of nuance, it all comes down to taste.