I would say rather than having them just change your trans fluid, you might consider having them change the fluid AND the filter. When I bought my VX it had just under 30k and I was shifting hard. When I drained my fluid it was BLACK and smelled way burnt. I changed my filter too, and ever since I have been shifting smooth as glass. Just a suggestion. I am gonna do another trans service on mine at 60-65k.
Bart