I have 43K on my bike, 21K in '06. Cam chain tensioners are expected to fail between 40K and 50K. I am not worried about "breaking even" on the ESA since I ride year 'round in Georgia and am semi-retired.

But people's riding profiles, based on bike useage and riding styles, are different; so the decision on the "worth" of the ESA is pretty much a personal choice and what was a "good" decision for me (at least in my own mind, LOL), may not be for the guy who rides infrequently, is very gentle on his bike's motor and drive train, etc.