When I unpacked the mattress was certainly not unpleasant or pungent odor to the fore, it smelled only for a few seconds after "new mattress", nothing flashy or annoying.
After almost ten hours, the mattress was then deployed already complete and could be used. It is in essence already hard as described, but it is on the surface still being pleasantly soft.
For this price, you will be hard pressed to find something better.
Therefore rightly five stars - you can buy without hesitation.