First of all, it's Treso, not Tresco.
Treso nipples have two significant features that, in my book, stand out: they are made from a proprietary alloy called Ampco bronze and they have a very small flash channel. The result of these two features is increased ignition reliability, both in terms of increased probability of ignition in each use and longer life (more ignitions).
The Ampco bronze is very hard and resists gas erosion in the flash channel much better than regular steel or even stainless steel. This means they last much longer.
The small flash channel increases the probability of success of an individual ignition event by concentrating the hot gases from the cap in a smaller area; a large diameter flash channel allows the gas to dissipate quicker. This is not normally an issue with a new nipple, but as the flash channel wears it can become a problem. By using a smaller channel and the Ampco alloy, Treso nipples perform much longer.
I don't believe there's any impact on accuracy.