Heard them on a '99 today. They definitely sound better than stock. I still think both the Muzzy and Jardine sound better though. You might want to ask about Sarachu. Been hearing good things about them.
Cobra F1 slip-ons sound *ok*....but they're a little ugly IMO. Stock-looking polished canister, with a big red F1 slapped on the side. No cool logo, no metal badge...just a big, tacky F1.
I've heard sound clips of Sarachu pipes and I have to say I'm very impressed. They sound AWESOME...but they ARE pretty loud. Filip has the Sarachus, maybe he'll chime in on the volume and sound characteristics of them.
Edit: Nevermind! Looks like you got your Sarachus!
Yeah i have an f1 on my '96 500. Personally i love the deep growl it gives off and it's really loud. It came on the bike so i can't really compare it to the stock exhaust, but i'm sure it's a big difference. Unfortunately though if your looking for apearance as well you won't find it with the F1 because as HalfLiterBeater said they really are pretty ugly. hope this helps