It is definately not a bad habit to get into for previous mentioned reasons, at the least your trueing up the mouths and necks.
For me it really depends on the rifle and the intended purpose of the load. I have mostly all stock factory rifles, however most of them deliver exceptional accuracy through the load work I have done with them.
A couple of them, however are mostly exclusively shot at under 100yds. The loads I shoot in them will group plenty good at these ranges, and unless there is a very noticable defect in the mouth or neck, I sometimes just grab up a handful and load away.
That said, for the rest, I pretty much full lenght size, trim lenghts, standardize the primer pockets, clean flash holes, debur, and then load.