Just look it up, some people complain about it.
Its only a problem with bigger movement, when you have to like trace someone right in front of you. It can't properly keep up with it. Like when a T shoulderpeeks a corner when you're close, so you swing your mouse to track him, then he goes back and you track him back. Usually my crosshair with the g203 is still processing my swipe to the first direction, even though you're swping the other way already.
Its nothing terrible, but as a sensitive whining motherfucker it just gets to my head, just like a few others with the mouse.
Great mouse, pretty good sensor, but it isn't flawless.
(i did play like a god with it though)