Actually, though I'm a firm believer in the Unichip... I don't know if that one will be the fastest... Kevin Limjoco's Santa Fe is chipped, and he claims that the 0-100 time went down from eleven and a half to around nine and a half seconds.... hmmm... drag race the two?
But personally, a chip that's progarmmed on the spot, to your specific vehicle, is worth the money. I think what you're getting with the DPChip is the plug-and-play harness, which makes installaton, tuning and removal much less of a hassle, and provides a neater installation. Unichip also has a plug and play harness, but you have to order it, and the extra cost will make it cost as much as the DPChip.
If the plug-and-play harness matters to you, the DPChip is a good buy, provided that dyno-tuning on installation is included in the package. Otherwise, personally, I'd go for the Unichip, since it includes dyno-tuning and optimizing in the package.