Many of the Cat dealers have inhouse labs. Might be closer and quicker than sending it out. I tried it years ago. At that time there wasn't a comparison for synthetic oil. For the average person, I don't think the sample kits are as available as they could be.
When you have large trucks and heavy equipment that you put a lot of miles and hours on, the tests are worthwhile. Truckers can use them to save money by adjusting oil change intervals. Contractors get a heads up on when an engine or other major component is getting to the point that maintenance is going to be needed to avoid a breakdown at a possibly inopportune time.
For the average Joe who takes care of his equipment and doesn't put the hours on that a business does it probably isn't worthwhile unless you find out you have a dud design engine in a new vehicle that you expect to have problems with. Then the test data might be useful when you go eyeball to eyeball with the manufacturer. You could prove the engine was experiencing internal problems way before it should have in spite of following the manufacturer's recommended maintenace (which you followed).