believe it or not they actually compare very well and even seem to be a not bad machine. but what features do you want? dc or ac/dc pulse? multi process? and there are other very good brands other then miller depending on what your looking for
equal length headers and y-pipe will the biggest factor in minimizing rasp, but there will always be some with a big v6 they will also flow better and make more power because the exhaust pulses aren't fighting for the same space in the exhaust
@sdxrunner619 has had both major supercharger kits and is now ls swapped and says that hand down dollar spent vs performance gain the ls is by far the best option