The really new feature of the MX 700 is its new cordless transmission technology, called Fast RF. This is still radio frequency, but the number of mouse-receiver exchanges per second has gone up a lot as it is now 125 instead of the average 50 on an ordinary cordless mouse. And as Logitech says, this is also the top limit of exchanges possible with USB. So, in theory, the lack of a cord is no longer a source of lag in fast movements. This should be the first cordless mouse to suit players of first person shooter-style games. While we are on the subject, compared to PS2, USB is a step backward for the mouse, because PS2 can handle twice as many exchanges per second. That said, quite frankly, and even though the sticklers will criticize, the speed of exchange in USB is quite adequate for a mouse. To make their cordless system even more efficient, Logitech have ensured that the data prepared for the PC is as short as possible between capture by the sensor and sending. This means there will never be a bottleneck of data, so no data will be lost. And in use, this definite improvement is really noticeable. You won't detect any lag in relation to a wired model. We got our fragger pro to play and he corroborated: "This mouse deserves the label 'Approved by hardcore gamers.'"