this is a great mat and there is no smell and it flattens out nicely. My only problem was the initial delivery with a tape that left a residue that couldn't be removed.
As another reviewer also said Staples ships this bare and open. They left it on the ground on my front porch. Between the dirt and the stickiness from the shipping stickers you start off hating the mat before you even use it! Once cleaned up and in use it actually is a good mat. So pick it up at the store if possible and you'll be set!
I've only used this mat less than a week and already there are divots in the mat from my chair wheels. I say "wheels" because my chair is a standard swivel office chair by which the wheels aren't always in the same position versus legs of a stationary chair. Not cool.