i have an OBX test pipe..well i techinally think its just a bolt on resonator..it was 45$ on ebay..but have to weld your own 02 bung on it and of course do the defouler trick
i give the megan an A. I actually have their header set too, it came with it for free. I paid 230$ on ebay. At the time I had a stock cat back on, it made it slightly louder but not much. Now I have an s2000 exhaust, its a little louder but nothing annoying like other brands. Megan test pipe is slightly thicker than other, so it acts as a resonator.