Point of reference, my Nismo exhaust took 15mins to bolt on to my Stagea... including time taken to put the car up on the ramps.
Why so quick? Japanese "bolt on" is exact.
In comparison the Stillen took us about an hour and some not-so-subtle persuasion (large rubber mallet) to fit it in place.
Nothing at all went wrong with the install.
Yep, very true, The Yanks definitely have done more for the VQ35 than any any other nation and if you are going to build an engine, the US is where you turn... but for bits like exhaust, suspension etc you seriously can't go past the Japanese for quality, performance and fitment.