Does anyone use a white brothers R4?

I was wondering if anyone used a White brothers R4
one their 400 ex if so what kind of power increase
does it get and what kind of sound does it have.I'm getting ready to buy a slip on exhaust and i'm looking them all over.i want a pipe hat gives me more low and mid range
rather than top end.Becuase i also drag race it.But I also don't want to get one that extremely loud either so if anyone has any ideas i would more than appreciate it.

Thanks

[Kadafiy]

I think the E series and PC t-4 are the quietest aftermarket exhausts. (94 dbs I think) I have a HMF and it is pretty loud. Shop around and search the old posts and you should find what you need.

[James70214]

I got the r4 on my 400. I like it aot. It gave a pretty good midrange increase. It is quite loud though. I want to get a TC pipe now.