With the 4-1 pacesetter you will gain a bit of top end, like you say between 3.5-5000. Not much difference in the low or mid range, maybe just a slight shift in the powerband towards top end. Will also depend on the size exhaust you get. I think both are good options, with the tsudo more difficult to install and more potential for leaks. If you go with the pacesetter, have the ball flange cut and a v-band and flex pipe welded on for a solid setup. As for some sound clips, here it is with magnaflow highflow cat, resonator and muffler.