I've got to be honest, I've never really trusted Sixth-Element. They just seem like a marketing exercise - I know all companies do this - but when I go to Sixth-Element all I can do is select wheelsets - I can't buy rims - and I can't really get much detail on rim specification (though I have just found several clicks in the internal rim width).They source there carbon rims from Asia like 99% of wheel builders, then they build the wheels based on which hub and Spokes you want. Lifetime guarantee which also allows you to sell and transfer the guarantee to the new owner.
Sixt-Element seem like they are setup to sell a wheelset at a price to a first-time upgrader - that might be unfair but that how it feels to me.