ha - fair point

I wonder if the Brooks gauntlet is cut in such a way that the button is superfluous?  That is, I've never really noticed it opening.  One of my Chang shirts is without this button and the gaunlet stays closed.  I mean granted, I usually don't practice spastic movements and flap my arms around, but still, I think with a longer garment, the button, it is needed?  Or what.

What say you to pleats at cuffs v. shirring. 

I like the shirring, though a launder rarely gets it right.  But I usually do my own shirts now.

Having tried it both ways I prefer a gauntlet button.

I prefer shirts with a gauntlet large enough that you can lay the cuff out flat to iron it easily. The larger slit in the sleeve means a gauntlet button is generally needed to stop the fabric from flapping open too much as you move your arms, thereby distracting people with your pasty under-arm skin.

On my (RTW) shirts without the button I'm always looking for it to do it up!

I have never given much thought to the reason for gauntlet buttons but I assume that having a larger split in the sleeve opening enables you to roll them up more neatly if you wish to do that? Seems like a good idea and it's a pleasing little detail, but it wouldn't be a deal breaker for me.

There ought to be a rule!

I find it doesn't matter. On the shirts I have without them the openings seem to stay pretty well closed. The bulk of my shirts are Press, Viyella, Barbour, Facconable, and Orvis and all of them have the gauntlet button, I think. I'll usually button them, but sometimes the laziness is so strong even this is too much of an effort.

The shirts I can think of that I have that don't have them are Brooks and Tyrwhitt dress shirts.

I will admit to removing the extra cuff button on sport shirts if I need to use the larger option. I cannot stand seeing the extra button on the cuff. But that's another thread.

It's easier to iron a sleeve without the gauntlet button.

Clearly, this fine attorney in Washington D.C. does approve of the gauntlet button:

http://dapperdistrict.blogspot.nl/2009/12/faux-pas-gauntlet-button.html

Personally, I don't have a need for them, but then again all my shirts are so so well-constructed out of such splendid material, and so well-tailored to my body, that the gauntlet stays closed gently but resolutely around my arm, as though it were a woman unaccustomed to feeling anything so intense as the newfound love she feels for me.