An interesting difference between FDX and UPS is that all the FDX ground trucks are contractors. FDX can shed costs really quickly in their freight and ground operations.
We ship stuff by the truckload on FDX all over the world; we have not noticed any drop in service.
I have no first hand experience with residential service of late.
The FDX Ground contractors get screwed. FDX has been sued many times over fraudulent inducements. They usually give the money back invested and find some other sucker to do the work.