Keyboard response is good. The cursor jumps slightly. Scrolling the wheel doesn't take much effort. I wear headset with mic and people hear me clicking.

I like the mouse because it tends to stay connected, the battery life is very good, it's not too bulky and fits perfectly in my hand. Sleep mode helps extend battery life by a huge margin.

Even if you do get an m557 that lasts, this mouse has very sub-optimal ergonomics. For the money, consider a different model. Only this overpriced basic mouse. Logitech is very overrated.

Bluetooth connectivity goes in and out. It disconnects easily and then my computer has to be rebooted again before the mouse will reconnect. It seems to be interfering with my bluetooth ear buds.

On a steelseries pad it sounds like sandpaper. It misses clicks, meaning i press on it and the click doesn't register. I believe the left button is faulty, but am outside my return window already.

It seems to happen at the most inopportune times. Now it malfunctions with fresh (tested) batteries. I hope the seller can resolve my issue.

Small, narrow mouse with glide feet that don't glide, it's just off. Scroll wheel is also very slow as it doesn't roll quickly and it also freezes.