Left for about 7 years and have been back for 5. Overall a positive experience. A lot of the same issues are still there in some form, but I feel I’ve grown and am better able to manage them.
It kind of gives you a chance to reset your value to your company. It seems that some perceived ceilings that were there before are now somehow gone because you come back with more experience (and as someone said before, leverage).
If you left on good terms and generally enjoyed what you did there, I think it can be a good experience. It has been for me. Just assume that whatever issues or problems that made it challenging before are likely still there in some form or another.