Tried the Crest 3D Professional Effects and they work really well absolutely recommend them to anyone.
The only problem was with the £22 import duty and parcelforce extra payment I had to make :( So just bare that in mind when you buying from outside of the UK guys.
The ridiculous EU laws that state only 0.1% peroxide in England because they may make your teeth sensitive for a day or 2 is a joke,
But you can get any amount of plastic surgery and it can go seriously wrong but that's OK with them.
Smile-With-Style co u k