I have 31000 miles on my car and I changed MT fluid for the second time (first one was done at around 3,000 or so) and notchiness is pretty much gone. After I changed it the first time, i didn't really feel much difference, but this time I can tell that there is a lot of difference

 

I've been thinking of doing that too. Lately my notchiness has been getting better, dunno why (haven't changed fluid since August). I'm thinking of changing it again sometime this spring.