Minor things first: Nothing really bad in general, so I prefer to call them minor. I wish there was a way to control which lights and frequencies to use, as well as the ability to set static lighting. The charging port is on the back of the mouse, rather than the front where wired and wireless mice are typically found. It would be great to have a double-click button as you have most gaming mice. Usually the double-click button keeps the finger from fatigue for gamers or just long-term everyday use. The scroll wheel is a bit loud, but the resistance feedback is useful. BEST OF LAST: I have a wired gaming mouse that is a little big but has a color change like this one so I bought this smaller one. The hard case it came in was a very nice touch. I love the wired/wireless connectivity and the ability to turn the mouse off with a switch and use it with or without the backlight. It also turns off after a short time to avoid wasting battery. Just press the button and it will wake up instantly, I mean INSTANTLY. I expected that there would be an annoying lag from the moment I wake the device up by pressing a button and moving the cursor or button to select a button on the screen. NO delay, the color change is instant and consistent. The forward and back buttons work great and the buttons are really quiet. This is probably one of my favorite features. Whether you use it for gaming or work, it's nice not to hear constant noise.