All you read below is just my IMO.
I had the same thought as you, but came to point that I don't need the powercommander.
It's primary function is to be used with aftermarket exhaust system and high perfomance air filter. You may install all of these things, but you never receive such perfomance boost out of them on DN-01 because of the one thing:
Catalytic converter is huge and it stay just between engine and muffler and even aftermarket parst for DN-01 is just a muffler, not the entire exhaust system. And installing a custom muffler will not change almost nothing, because the catalytic converter is the greatest stopping power for exhaust gas in DN-01. If you want to take some perfomance boost out of DN-01, you need to cut off the catalytic converter from the system, just like I did, or IMHO you can spent a $500 for powercommander, $50 for air filter and $300 for mufller more effective than this.
