There is a lot of difference between the two. Power Commander is a very clever way of tricking the computer into doing something different than it intended. But it is a little like hanging colored cellophane in front of a Black and White TV. It is interesting, but it ain't memorex so to speak. It was the only way to affect a tune on the early FI systems that did not have an EEPROM chip. The EEPROM (Electonically Eraseable Programable, Read Only Memory) can be overwritten by a computer. Tune boy lets you do this.
If there were a case where you wanted to increase one part of the table and then decrease another part and finally leave another part unchanged, that would not be an option with the PC (AS I UNDERSTAND IT!! BIG CAVEAT HERE, lots of big words, BUT I barely know what I am talking about!).
In addition to the fuel maps and ignition timing the tune boy gives access to the secondary thottle plates, REV limiter and the top speed limiter. It also allows you to correct the speedometer, but only 1/2 way. That is, on the speedo you can have the true speed, or the true miles traveled, but not both. That is because of how it is geared.
So the Power Commander is awesome, it does a great job and is easy for tuners to use, but it is still hanging a piece of cellophane over the screen. Tuneboy is harder to tune with for the shops that are set up with Dynajet, (Power Commander), but it does more AND you can load a tune yourself in about one minute, especially after your buddy e-mails the tune to you. Hmmm... Not really a simple choice, but it's all good. Just ride and have fun.
