The 10 year ones are basically only guarenteed for 10 years. some people think the lifetime ones are only lifetime of implant!! their wrong!! lifetime ones are naturelle implants and they protect you for your lifetime fpr example if it ruptures in your lifetime they will cover the cost of the implant but not surgery. however they do not cover u if they start to sag etc. I think your paying all that money so why save a few hundered om implant when they cost around 400 more (or not if you haggle) cos in long run if u have to have done again u will save 1000 for not having to pay for implant if it ruptures with naturelle. everyones personal preference though xx