Comments by James have caused doubt that concerns are justified, by throwing in the Vtec comment.
In all fairness, my car had a exhaust tip reading @.5m of 102db@4350rpm prior to the headers being spread, and now has a reading of 87db (checked by exhaust specialist)
As yfin stated..
Vtec is one thing, but harmonics and metallic vibrations are something else.
Don't be confused between the two for those who haven't heard the difference!
My final prototype system is due to be replaced with the production one later March, so personally I can't comment on the final product until my headers etc have been replaced. (Has been 3 1/2 months wait so far)
So personally, for my euro, it is only the slight harmonics that persist along with a metallic vibration @3.5-4k.
If these matters are sorted I will be a happy customer, if not, well, I didn't get what I paid for did I?...........hmmm