Id go with the white trays myself. Ive tried the white strips and what i didnt like is the area they whiten isnt that big. while they do work if you were to ever show more of your teeth than what is seen in a standard smile you can tell you whitened your teeth because the back and side teeth will still be dark/stained. The whitening trays whiten all of your teeth. I believe aquafresh makes the trays although i have yet to try them the idea just seems better IMHO