Best Chain Tensioner?

My issue with the Surly is that the spring seems to be identical to one used on caliper brakes, and it's not really up to the long-term task asked of it. Basically the leverage required for a tensioner is greater than what I feel the tolerances of the Surly spring are for it's working life. I like the notion of using a spring with a long arm at the end to increase the leverage power of the tensioner, this should make it more effective too.

No probs with my surly, daily use for 3 years now on the same spring, its fine.