I never noticed it until he pointed it out. But, I wasn't driving it and I didn't pay $29,000 for it. So I understand where he's coming from.They made some changes to the 5.3l since mine, but I couldn't really tell with mine unless I was looking for it (or looking at that display screen). It was pretty slight. The engine sounds slightly different too. Chrysler's system is a little bit more seamless.
Have you noticed it too? He could be neurotic about it or there could actually be something wrong with it.