I have two Sensei Raw mouses, one is 5 years and the other one is 7 years. Because the older one generates a high pitch sound from the sensor which is quite annoying I am thinking of buying a new one. However, the Raw is discontinued. Then I ordered the Sensei Ten.
With a new optical sensor, the Sensei Ten does not have the noise. The shape of Ten is the same as that of Raw. But I feel the quality of Ten is lower than that of Raw. First, the button is quite rough (Button 4-8), like a 10 euro cheap mouse. Second, buttons 1 and 2 are stiffer and a little bit laud when clicked(maybe because it is so new). Third, the cable skin is made of rubber which is not braided anymore and it is easier to be broken. Fourth, the wheel is not as smooth as before and the harder rubber on the wheel is not comfortable to touch compared to the previous one. One advantage of the new one is the RGB light, however, the log is painted with dots anymore (I prefer the dots).
more comparisons can be found in reference 
After one month, the Sensei Ten generates some noise from the wheel. The light of the wheel will turn red when gaming.
(2 months later the other Sensi Raw has a wheel problem, and cannot rotate smoothly, buy additional Sensi Ten)