The "chemical smell" of some already reported is discernible, but does not bother me personally. So prominent he is only detectable in my perception is not, and after about two week use, if I hold my nose just above it.
A little annoying but noticeable shortcoming is: The fabric coating has a "bottom line", ie, the fibers are towards the gel pad, so that a definite resistance is felt, is moved when the mouse (or a finger) from the pad away. When the sliding feet mouse protrude slightly, their movement can sometimes easily hook. There is also a slight scratching noise. I have the mouse while being replaced by a trackball, which is static on the pad, so that does not bother me that at the moment. With a normal mouse but that is uncomfortable. Whether this is the time, I can not judge, because I use the pad only recently.