Product review (5 stars): Flexible, easy clean up
These are perfect for what I wanted.  They can just lay in the bottom of the oven or put them on a bottom rack.  They don't cover the entire rack so you can still have good heat flow around the oven.  They are easy to wipe off and keep clean.  Also, with a five burner stove, they can be cut to fit around the burners for a solid drip pan instead of pieces.