The backache happens, because the spine de-compresses with inversion, and then begins to compress again when you stand upright. If you can, stay flat for a few minutes before getting off the table. That should reduce the back ache and allow sufficient time for spine to adjust.
Although rebounding has been promoted as lymph cleanser, I feel rebounding still puts jerk on our disks. ( Though not as much as jumping on hard ground). Our purpose is to take the pressure off the disk and not increase it. So I would avoid too much rebounding.
Yoga therapy is more beneficial as it helps in increasing the flexibility of the spine and lymph cleansing.
It all boils down to how healthy our spine is. Good health comes from inside out.