We need all the good posts from the 9000 do I need small base dies threads in one big thread.
Many people use standard dies and have no problems at all, but even if the rounds chamber fine in their semis, there is always the possibility (due to tolerances etc) that there are guns out their they will be tight or jam in.
I agree with SlamFire1 that brass life is most likely a non issue with small base dies as long as you control how far back you push the should, as that is the biggest culprit in wearing out brass.
But again, if you do not size to minimum headspace, which will work brass more than just pushing the shoulder back say .002 to .003 or to maximum headspace etc, then again, there may be guns out there with minimum headspace that will choke on them.
The cases must be small enough in diameter as well as having to shoulder pushed back to minimum headspace to make sure they will chamber in any gun with proper headspace, (From min to max.), and even then if a gun has under minimum headspace there could be problems. Most don't though.
I use standard dies and size to fit a Wilson gauge. They run in my guns just fine.
If I was loading rainy day ammo that had to absolutely work in any gun, I would use a small base die and size to minimum headspace, or use new brass, or buy new ammo.