It has been seven and a half years from when I first saw the SteelSeries Xai at CES. A few months after that I had one in hand to review and from that point on I have been using a variation of that design, mostly Sensei's on my main computer and/or other computers. It was never perfect, even back then I mentioned the sensor having a few issues but the overall shape and balance was great, so great in fact that it has spawned multiple mice from other vendors trying to capture that same design. But for a few years now the Sensei has been feeling dated with so many other mice getting great optical sensors so you can imagine my happiness when I found out that SteelSeries was introducing a new Sensei along with a new Rival, both with their new TrueMove3 optical sensor. Now after seeing some images of the design I was a little worried that they had messed with the shape and it might lose what made it so special. This is a huge moment for SteelSeries and given how particular about the mice I use when not testing, they will have to get this one just right for it to replace my old Sensei. So let's see what the big deal is and then put them both to the test.