Is it worth a tranmission?

I hate to say it after ready all the great things about these trans, but I can tell it is on it's way out. I ran stop slip threw it and it seems to be helping a little bit but it is starting to slip between 3rd and OD again and it takes a second to shift into 3rd. I had a newer engine replaced with around 90000 on it, but my question is it worth rebuilding/getting a new trans installed? Or should I run it to the ground and go from there