I don't know about any of that Answer stuff but I've got the T-4 on my 400ex. Pro Circuit makes high quality 4-stroke pipes. The fit and finish was great on my pipe and came with perfectly matched mounting hardware. It looks good, sounds great and is a lot lighter than stock. I purchased the quiet core and was disapointed. It sounded like crap with that in. Other than that it's great. Ask anyone that rode it at haspin, it's sweet.
'02 Honda 416ex - A seasoned blend of 11 herbs and spices
'04 Honda Recon - The yard machine and snow plow
'88 Honda CR250R - Another chapter in my torrid all terrain affair