Like Kenny, I have the BUB slash cuts. Really improved performance and good sound. Not so loud at idle so that the neighbors complain, but plenty loud when opened up. And I don't think they are high pitched at all. ('course I have some high frequency hearing loss from all the front rows at Zepplin, Sabbath, Humble pie, etc. during my youth).
Contra todo mal, mezcal; contra todo bien, también
