I have bulging herniations in my lower back (L4/L5 and L5/S1) and neck (C3/C4), and I have an inversion table, I use Teeter brand. It helps me, but I use it sparingly, as I'm concerned about too much inversion and the consequences that can have for capillary damage in the brain (I'm over 50).
Two things affect my neck more than anything - my posture (especially when reading, using my tablet/smartphone, etc), and my sleeping position. One I have immediate control over, the other one, not so much. I recently got a memory foam pillow, though, and that seems to have helped out a lot with the