You misunderstand, it's not that there is anything inherantly wrong with the DC sports Street Legal Carb exempt header, but there is no sense in buying it at all on a DOHC Honda.
J even without internals or big NA work a good quality, MSPi, SMSP, RMF, SPARKS, HYTECH header will outgain any DC header, even the JDM 4-1 with 2.5 collector hands down. That is something that you can not argue at all. On a built NA motor, even a small build like I had with just good cams, I, H, E, IM and tuning the above mentioned headers then make even more power. My point being, if you plan to ever go above just simple bolt ons don't make the mistake I did and think well I'll just spend 200-250 on this DC now and then "IF" I need to later I'll get a better header. Get a better header now and it'll be the smartest thing you ever do on an NA Honda build. IMO a good header is the best start you can make on a Honda period. There is a reason why the JDM DC 4-1 header is 300+ and the cheapest of those mentioned as "good/high end" are 600+. That is the simple fact that they make more power and are better constructed.