Curiosity killed the cat, and I've been using a G303 for the past couple weeks, primarily because I was interested in testing the notoriously weird shape. Maybe it would alleviate some of the RSI issues I had been having, just by encouraging a claw grip instead of a palm? Hell if I knew. I was switching from my trusty old DeathAdder 3.5G, which is the only other gaming mouse I've owned, so it's going to be the basis of comparison for my review.
Trying the G303 ended up being more or less like trying crack. It was a lot of fun, and it takes a lot of willpower for me to put the mouse down now, but I have to, because I just can't deal with the shape. Even after two weeks of use, the shape feels uncomfortable to me. I've tried adjusting my grip in subtly different ways, but no matter what I do, I end up developing RSI pains much more quickly with the G303 than with my DA. For the record, my hands are 20 cm from wrist to fingertip.
Now for the good news. Almost every other aspect of the mouse is god-tier, in my opinion. The click latency is so good that when I first started using it, it felt like games were proactively responding to my clicks a few milliseconds BEFORE I even made them! After I went back to the DA, the click latency was very obvious, and frustrating. The mouse buttons feel crisp, and have satisfying auditory feedback as well, which is impressive to pull off in combination with such light and responsive clicks. This is definitely my favorite aspect of the mouse.
The LOD is superior on the G303 (default settings, no calibration), too. It's low enough that it doesn't accidentally track while repositioning the mouse, a problem that I have more with the DA 3.5G. I don't feel like I'm hugely qualified to comment on the quality of the sensor itself, but I will say that after adjusting to the G303's 3366 for a couple weeks, then switching back to the DA 3.5G, I felt like there was a degree of negative acceleration in the DA (rapid, large turns felt like they took too long, and vice-versa). However, I could just as easily suggest that this was a result of becoming adjusted to a slight positive acceleration in the 3366. What I do know is that my aim felt reliable from day 1 on the G303.
While some people complain about the scroll wheel feeling too tight, I personally like the scroll wheel. It's easy to control each individual step on the wheel, so if you were the sort of person that liked to bind scroll wheel to a weapon selection cycle, you wouldn't have any problem selecting the right weapon. Middle mouse might be a little stiff, but it's not a big deal. The side buttons are fine, albeit maybe a little awkwardly shaped and positioned (again, shape is my primary criticism of this mouse).
The only other issue is, of course, the god-forsaken braided cable. It kept bumping into my monitor stand, which was pretty annoying. And I almost forgot to mention, I was lucky enough to receive a unit with zero lens rattle (1508 S/N).
TL;DR -- Logitech took an amazing mouse, and completely ruined it by putting it in a stupid spaceship-shaped chassis, instead of something designed to be comfortable for HUMAN HANDS.
Edited by dgmul - 10/16/15 at 5:02pm