I think its a LOT of money for such a minimal gain. Since you already have a chip, I dont think your going to get as big a boost as you would hope for.
The EDGE EZ is a commercial version of the 10k mod.
http://www.forgotton.net/mods/index.html
Link above explains how to make your own 10k mod. If you want to make it adjustable, replace the 10k resistor with a variable 0-10k resistor with a 3.9k resistor soldered to the center post of the variable resistor. That gives you 3.9k to 13.9k of adjustablilty, and if you put the variable in the cab and just lengthen the wires to reach the ICP sensor, you can adjust on the fly.
Also look up Blackcloud Diesel 18k mod, and SP Diesel Stage-1. Those are also basically 10k mods.
I also have a super secret source for the male and female ICP connectors :evil grin: