1990 Honda Accord 4 speed overdrive tranny

I contacted Honda and they suggested an additive called LUBEGARD. Honda said these particular tranny's are know for hard shifting. I drained the tranny fluid, put in the Honda Tranny fluid and a half of bottle of LUBEGARD. Within 2 hours I noticed a big improvment. I am in the process of re-painting my 1990 Accord with 100,000 miles and before I did, just didn't want to be replacing an expensive item (tranny) anytime soon.
The web site fo rhtis stuff is: http://www.lubegard.com/index.html

Wanted to see if anyone else was experiencing these symptons with their auto tansmissions.