I haven't used it long enough to give it a five. I'm sure it will get there...
After trying the peel-off whitening strips, dissolving whitening strips, trays and goop - just not good results. This says visible whitening in 3 days. I don't know about all that, but I've had it maybe a week, and my teeth look a little brighter, and BONUS, my teeth feel like I just left the hygienist. Pretty good so far. I'll try to come back in a few weeks and see what we come up with.
Rating: 4 stars