For anyone that is interested, I recieved and installed a Power Now device last Friday. I took my bike ('01 YZ426) trail riding for about 6 hours Saturday. In no way does this device add power, but in IMHO is definitely makes the bike much more "luggable", almost "XRish". I primarily race enduros and scrambles. I had gone to a 52 tooth rear sprocket to help navigate the nasties and avoid the dreaded pop stall. The down side of that is not enough gap between 1st and 2nd. My impression is that I should be able to go back to a 51 or 50 tooth with the help of the Power Now device. I don't see this device as being too beneficial for moto work but if you ride the woods you might consider it. I'm happy with it.