I have experience with this, too. Our cats, when empty, make the truck sound like a glass bottle rolling down a driveway. It is not a good sound at all and it is maddening inside the truck. It doesn't sound mean. It sounds broken.
Straight pipes? Maybe that would be good. But the passenger side cat has this little offset from the entrance to the exit of the cat that would make a quick cut and patch job, without a mandrel bender, tough.
Best throaty mods are to convert to a cone filter up front, get rid of the resonator, and go to a Flowmaster muffler. Side out exhaust (though the body panel) and you can listen to that rover heartbeat.
But the cat cake does really save your ears from an awful, terrible, not beefy sound from the engine. At least with the chambers left in place.