The GTR is not a handsfree cap. If you like to just set it and forget it, a maria-style cap is more for you as it generally will have a lower center of gravity and be less likely to fall off during a coughing fit. But if you like having more control over your experience, then the GTR puts that control into your finger tips.
The carb cap derives its name from a carburetor which in engines is a device that mixes air and fuel for combustion. At face value, the name seems fitting as we are using the cap to mix air into the oil but those who are familiar with how a carburetor actually works will know that the carb cap does not perform the same function.
A carburetor has an inlet/outlet, a choke, and a throttle.
In comparison a regular carb cap only has an inlet/outlet with the cap itself acting as the defacto choke. The amount of air that is mixed in to the reaction chamber (in this case, the gavel bucket) is regulated by the inlet/outlet of the carb cap on top of it. Assuming the draw from the user is consistent, the amount of air being mixed in to the chamber will also remain consistent. This is despite the temperature of the reaction chamber varying greatly through out the process.
With an engines carburetor, the choke function works by reducing the air intake. By having control over the amount of air that is able to mix into the chamber, choking the carburetor results in a gas rich fuel to air ratio.
Similarly having control over the air intake on a carb cap allows you to also have control over the vapor/air ratio being produced in the reaction chamber.
The GTR is unique in this regards as it not only gives you the option between vortexed and straight air paths, but also allows you to regulate how much air is being allowed in to the chamber. By regulating the air entering the chamber, one can regulate the vapor quality despite the fact that the reaction chambers temperature is rapidly dropping. The GTR has 3 variable wind speeds:  Full (No intakes blocked),  Medium/Vortex (top intake blocked),  Restricted/Straight (side intake blocked).
For example, here is a thought experiment: We can assume that a quartz floor at 600 F will produce a richer vapor quality than one at 400 F (both using the same traditional single hole bubble cap). The reasoning seems simple. The floor is more active at higher temperatures and the amount of air mixing with the vapor remains constant. The results are a rich vapor quality at higher temperatures and poor vapor quality at lower temperatures.
Now imagine a cap that has variable control where it can allow "more" or "less" air into the reaction chamber (a variable choke). Using this cap on a reaction chamber at 600 F we can allow more air into the chamber, which lowers the richness of the vapor quality being produced inside. Inversely, at 400 F we can switch to allow less air into the reaction chamber which increases the richness of the vapor being produced.
That is essentially what the GTR Cap is. A cap with a variable choke, and great directional control over the liquid.
In todays age of infrared thermometers its not often one would choose to use one at 600 F but if you are still using timers you may find yourself there and by allowing more air into the chamber you may reduce the unpleasantness of that experience.
Furthermore, the caps ability to create either a vortex or straight shot wind patterns in the bucket shouldn't be understated. When vapor is being produced, the floor at the nucleation site is drying, rewetting and drying itself again. Having the straight shot channel allows you to push the oil to the dry areas of the surface where the heat energy remains. And one can exploit the vortex channel to force the oil up the walls where they will find new energy to use in the process or use the vortex channel to spin pearls which certainly assist in the process at lower temperatures.
When all is said and done, I have used many caps over the decade, and the GTR cap seems to always find its way back to the top of my nail for the reasons stated above.