Be ever so careful when handling sensitive electronics. Like i said before, make sure battery is disconnected. Before you touch any sensitive components, discharge any static that may have accumulated on your person. How?? Touch a grounding point, you know, when you touch something and get that static zap, thats you releasing a static charge. If you release that to the ecm, it will damage or fry it instantly. Also, the light coating of di-electric grease will prevent corrosion that will do two one of a few things; block or impede current at a connection point, short two or more connections, and a few other things that don't come to mind immediately.
I have heard of more people that have had good experiences then bad with Power Commanders, and usually the ones that have bad experiences are the same guys that come right out of the bar doing burnouts. I know, burnouts on a cold motor have nothing to do with computer controls, but it does exhibit a negative pattern of how one takes care of their machine.
The ease of tuning a PCIII or the complexity is nice because you have so many options of what to do with it. You can narrow down certain rpm ranges, throttle positions, and then you can set each point for % of fuel and degrees of timing. You can even adjust each cylinder individually or together depending on what you want and how much effort you want to put into tuning your bike.
As always, good luck!!