Hardware nylon locking nuts. What are the advantages/disadvantages of low profile nuts like Shorty's?
The normal nuts and low profile nuts, also called jam nuts when I looked them up and bought a box from a hardware wholesaler are pretty much the same overall apart from the height.
When I was using shorter bolts with very thin rubber risers, I could fit everything in nicely with the low profile nuts, whereas I couldn't fit it all in on 7/8" bolts with the regular nuts.
The whole idea of this back in the day was going from long bolts with taller nuts, down to shorter bolts with lower nuts to minimise any grab issues and a lot of people preferred this as they could set up and take apart boards way more quickly too.
Preferences in board setups aside, some people find the low profile nuts just a pain as their skate tool might often slip on them, but a decent or slim skate tool that fits squarely on to the nuts is fine, especially / even with trucks like Venture or Venture low which are known to never really get a thicker tool to fit cleanly onto the nuts beside the pivot housing.
Both the normal and jam / low profile nuts are available from wholesalers or hardware specialists too, so often just replacing the nuts as needed, rather than the whole set of nuts and bolts is a game changer for me, in the skate shop, reason being the nyloc material starts to have issues after a few changes, so then they end up not holding the trucks on firmly, so changing to fresh nuts makes all the difference.
Without nyloc, nuts will not stay tight, no matter what you do, so having nyloc that works and holds is essential to the good working order of a normal skateboard.
From a madness perspective, having nuts that loosen off is very frustrating, so there are some people I know who will change out their nuts every second board or so, just to ensure they have nice tight hardware.
Seeing people who have deck bolts literally fall out of their setups through not tightening down their nuts is mind blowing to me, along with those who have truck holes that have ovalled out so much that their setups look like they can never run straight either, along with the trucks not lasting half as long or the decks having very wide gouges in them from the trucks moving side to side every time they try something.
General rule - if the nut can be finger tightened all the way on, it is time to replace them. That goes for kingpin, axle and deck bolt nuts, all of which can be bought separately too.