Should I be concerned about the timing chain stretching on the 3.6L engine?

What is your question?

I am interested in purchasing a 2007 STS with with the 3.6L engine and about 75,000 miles on it. However, I am concerned about all this issues I have been reading about with regard to high oil consumption and the timing chain stretching. The car even has a special GM warranty whereby GM will replace a defective timing chain within 10 years or 120,000 miles, whichever occurs first. Based on what I've read, this timing chain failure is inevitable. Any thoughts on buying a car like this or should I just pass?