I've got the Supertrapp on Stella the STT. LOVE it. A good lopey idle, cruises smoothly and not too loud but really ramps up when your on the gas
I get substantially more ground clearance, the stainless is really nice, and its really light. I used a fairly stock Jardine type race tune that runs really well. I installed it in less than half a beer.
I've bolted on the cone ones before (they are local to me) and they are louder for sure and a bit more 'snappy' sounding (especially with no turn out!). I know a guy with a 1250kit on his Buell that has one and he really likes it. Neither would require earplugs IMO, but they aren't quiet.
How much are they?