Yeah that's right, converting to part-time 4x4 where the truck only operates in RWD. Doing so means the front drivetrain isn't spinning during normal driving thereby getting rid of any potential vibrations. The other benefit is that nothing is spinning up front meaning you eliminate the wear and tear on the front end internals. Especially good for those running chromoly Birfields which have shorter wear life.
But it's not a simple mod, nor cheap. Slee's part-time kit is about $800 and involves opening up the transfer case. You then install the locking hubs. To keep the truck in RWD during normal driving you need to have a CDL switch.
So in my opinion, even though it's more expensive than a DC shaft it's a better solution. A DC shaft is just a band-aid to get rid of the vibrations, an expensive band-aid. The real solution is to disconnect the whole front drivetrain. Here in CA there's no reason to have a fulltime 4WD vehicle, we hardly even get rain!