I have read in other threads on other forums where owners got some good benefits from them and were happy. I do extended warranty inspections and often find safety and usability issues owners were unaware of, some significant.
The last two owners had bad home hookups they were unaware of: 1) one had a bad ground, used a lightweight cord and had low voltage. 2) the other had a bad connection between his extension and rig power cords.
One owner had just purchased his one year old used Class A and the front cap had problems with the seams, either from damage/poor bodywork, or improper mfg installation AND an unusually heavy amount of chassis rust.
Another owner was running outdated tires he had recently purchased at a good deal.
So, I do know the inspections have value in connection with obtaining an extended warranty - at least the ones I performed have paid for themselves up front regarding safety and user issues.
In general though I'm a great believer of doing inspections and most of the service work myself, which is why, despite being retired, I have taken inspection and service training, and worked hands on for a short time at a dealership.
But I also do other weird things like reading the classics, rather than entertainment novels.
This time next year I will probably buy either a Seneca or a used Newmar dp.