[stupidglide]

Smart maintenance is key, and quite honestly, how it was broken in has a tremendous amount to do with the longevity of ANY air cooled engine.
Good ring seal propagates long life, as it keeps combustion by-products to a minimum, allows the engine to work at peak efficiency, and keeps lubrication contamination to a minimum.
The only problematic issues I have seen with the 96" engines, are the aforementioned cam chain issue, and either keeping an eye on it, or converting to a gear drive cam setup, and you shouldn't have any major problems.
I beat the ever-lovin' snot out of the one in the 2009 FXD that we had, and it ate it up and wanted more. That motor ran VERY strong, and every time I changed the oil, it was still pretty clean (I changed every 3000 miles, and used Amzoil from George)

Good luck!