Just so you can be all caught up, there is also a whole lot of inner cam bearings that go bad. This usually destroys the engine. (not re-buildable). Loose rollers inside the case is a bad thing, for sure.
A gear drive cam set up eliminates the chain tensioner thing but it must be difficult to fit up correctly because a lot of those have a loud whine which may be from the fit of the gears, I'm not sure. There is a much better bearing available for the inner end of the cams too.
A good practice is to pop off the timing cover and have a real close look at around 25000 miles.