My last 3 bikes iv had Jap spec Yoshi slip ons which are well made and sound the dogs, on my K5 i have the titainum with set valve. Its exspensive but worth it and you get a nice flame out of the pipe !!
I'd have to say that I rather like Blue Flame, the twin out put cans look damn good and sound great. Just can wait to get rid of the long stanless steal can and get my old titanium can stubbied