I have a gutted exhaust I picked up, and although I haven't had it opened up on the trail, I have ripped across the back yard, and I wouldn't say its MUCH louder, just a bit, and a nicer tone. But sound is a matter of personal opinion...just adding mine. I also have a ZRT 800 with PSI pipes and DG silencer. The RX is whisper quiet compared to that! I was actually hoping for a little more aftermarket street bike type of sound, but it still sounds very good. I bought a gutted exhaust, so that I still had my original to reinstall or modify further and experiment with.
Of course, I did the required sound test with the exhaust completely removed, and although it sounded awesome, it was definately too loud.
Jim