For use in shower, are the Raised or Designer Grip-Loc tiles more comfortable to walk and stand on? How flexible are each of these? Are they a soft or firm plastic?

The Designer Grip-Loc Tiles would be more comfortable to stand on in a shower. The Raised Grip-Loc Tiles have a raised pattern on the top that may not be as comfortable underfoot. These tiles are very flexible as they are made from a soft EVA plastic. You can cut and fit these tiles to any desired shape easily with a sharp utility knife and a straight edge.