I think your experience is totally in line with what benz560sel needs to know. In the inline engines, if maintained properly, the timing chain is usually not a problem. With the V8's, however, you should stay all over the timing chain and it's components. The guides are known to break and wreck the whole thing, not to mention the chain itself. If you here even a trace of a noise, or have traversed a few miles, have it inspected and checked for stretch. Great engines, but they NEED this extra attention.
This is the ounce of prevention worth a pound of cure thing, except in this case it's about 10 ounces of prevention to prevent a 1000 pounds of cure.