I wouldnt call it junk, but several have had problems with them. I know once you go adding more fuel to it than an average canned tuner, several have seen 32-33 pounds of boost, and anything more than 32 is considered catastrophic to the ihi turbo. If you're staying low on your power added then it's ok. When I did mine, I opted for the kennedy adjusteable unit. Mine stock would hold 22-23 and I was already hitting 25 with it still setup like stock. I had some black I wanted to clear to a haze, so I only wanted to go to 28-29(the generally accepted max boost for an ihi turbo to live a reasoneable life span), and others with the ppe were reporting 32-33 with the ppe, so the Kennedy adjusteable fit the bill perfectly.
If you don't need more boost to clean up your tune, then added boost pressure just for the heck of it will actually cost you HP though. So yes it can be worthwhile, but its not for everybody.