I got the invisible shield. It ended up getting my nano wet. The buttons click and i think the solution of soapy water got in there. anyways, i spoke with them great customer service. apple also replaced my nano as it was having a minor issue before the water damage.

if the shield didn't require water, it would be the best protection because on a white nano it is invisible unless you look at it closely and know it's on there.

and the material is ridiculously tough and scratch proof.