Dig's chips are not the ultimate. Scott "Dig" is one heck of a chip and truck tuner. Basically, you buy a custom chip off him, you make some runs with datamaster or diacom, send them to him and he will reburn the chip tuned more to your truck. I can't remember the pricing on the his chips. You can probably find his email somewhere here in the BB.
The Ultimate gives you more options without having to reburn a chip for different timing, fuel and such. Either one is a good choice.