anyone used this

Yes but just how much power or horsepower is actually lost by running an O ring chain, is there anyone who can show figures.

It would an interesting experiment to find out.

Is it really worth worrying about and having a chain the would last a longer time.

I run an O ring chain and I am not complaining about any power loss, the ass dyno seems not to notice any loss in power.
 
i run a NON-Oring chain.... but thats just because i didn't read the full description when i bought it, i will be going with O-ring chain the next one i buy.