I just noticed that when the OP refers to "bucking/jerking/general roughness" he is referring to how the actual car feels/behaves when shifting and not the transmission or the gear change/engagement itself... Sorry about that.
Anyway, now u know that Nissan is acknowledging that these trans might experience grinding issues from 1st to 2nd or from 4th to 6th and that you might wanna keep it in mind.
