RGH3 , like Jtag , uses a chip that is already on the xbox 360 motherboard and that is part of the xbox's architecture. The nand is modified so that it uses that onboard chip to glitch the system. So it's like you have a modchip that's 99% installed already, all it needs is 2 more wires and a resistor. No chip has more features than RGH3, they cost more and are overall not needed.
RGH3 is your answer, case closed.