The other issue with retaining OEM piping, is that from a tuning perspective (doesn't matter which vendor one elects to use) the expansion of the piping side under boost, as mentioned by Glock, is that those expansions provide "challenges" let's say, to the tuners, due to varying boost conditions in relation to the contracting / expanding of the OEM piping.
By utilizing the hard pipes, this eliminates those challenges, provides a better platform to your chosen tuner, to make use of consistent, reliable, controlled boost conditions.
The prevention of split OEM piping is also another plus, as is the "eye candy" factor.
One detriment however though is heat soak, which is customarily not mentioned.
But as is the case with any given mod, there are +'s and -'s, so you have to choose what's best in your opinion, for your ride, as it fits into the overall mod equation.
Oh yea, and the "oh wow" eye candy factor? Over the top IMHO......
