Farkles

[Grumpy Goat]

The grip covers delay the heating process a bit.

That was my thought as well. Also, since foam (or more precisely, the entrapped air is also) an insulator I would bet that the heat felt at the glove would be less through the Grip Puppies than if there was direct contact between the bare rubber (also an insulator) handgrips. That is the tradeoff, I guess for more comfort especially one has large hands. No tradeoff if the heated grips are never used, or course.