I haven't heard anything yet about scores of people being nabbed because of loud pipes. I live north of Denver and have not ridden into the city too much. Went to this month's RAT meeting and there wasn't any mention of it (although it was a HUGE discussion topic a couple of months ago when they first announced the new "law").
So I'd have to say, so far, so good.
OBTW, that would be Denverite
