I put 93,000 miles on my Evo before I sold it, it still ran fine, never an issue.
The twin cam cam chain tensioner issue- the tensioner shoes were made of an inferior material that tends to wear out. I checked mine (2004 Deuce) the other day at 49,000 miles and they still look good but I have heard of them failing at 30K. Harley mechanic told me that regular oil changes with synthetic oil keeps them alive longer. The cheapest fix is to replace the shoes with an aftermarket shoe eg: Cyco brand. Can also go with gear drive cams which eliminate the chain and tensioners or install the Harley upgrade which is an upgraded oil pump with hydraulic tensioners that supposedly last much longer. There may be other options that I'm unaware of.
Harley changed the setup in some late 2006 models and all 2007 models so any 2007 + won't have the issue.