When was the last time you changed your transmission fluid?
I have been using Mobile 1 synthetic ATF. It's notchy when cold, but gets better when it heats up.
I have some Pennzoil Synchromesh to put in as soon as I get off my fat ass. I used GM synchromesh in the T-45 of my 98 and was very happy with how smooth it shifted (Pennzoil makes it for GM and is cheaper under their label).