Thompson Center used two different length nipples depending on the model.
They were however, both 1/4"-28 tpi.
The regular nipple was .635" in overall length.
They also made a "short" nipple, sometimes referred to as a pistol nipple that is only .500" in overall length.
The Hot Shot nipples, later packed by T/C have the same dimensions as the regular nipple (.635" LOA) with the addition of two small holes drilled through, near the top of the cone.
That is supposed to allow some gas to blow out, flaring the spent cap a little to make it easier to remove.
The flash channel in them was also supposed to be shaped a little different to encourage better ignition.
Cains sells a Spitfire nipple (made by MSM) that is supposed to "throw more fire at your powder", or some such marketing ploy and is the competition to the Hot Shot's.
I have tried both, which sell at a premium (albeit a pretty small premium - most nipples are 4-5 bucks), and didn't notice any change in the POI.
Don't know if they ignited the powder better because I don't get misfires on any sort of regular basis - so can't say they cut it down by XX% (and I shoot both Goex and Pyrodex - but do use mag primers when shooting the Pyro).
If you think they will give you some kind of advantage, DO give them a try.
Most shooters would be better served by tossing the nipple on their rifle once a year and simply replacing it with a "standard" nipple.