Yup the big gains happened when you dialed it in for meth vs just running meth with the old tune.. only chance a box has is awd / brake snip / four corners drag radials. / Meth / race gas / negative da ... / Catless / light wheels / no seats and non gt2......
For the most part I agree, but having the piggyback on top of the back end tune allows you to make quick adjustments.
Examples would be for WMI, Higher ethanol content fuel, or to put it in valet mode.
What works best if you want to take the plunge on flash tuning I think is just getting the best flash you can then using the JB4 for logging, safety systems, boost by gear, CPI/meth control, and fine tuning. We've probably done around 100 cars like this now and it works quite well. A lot of the flash maps need minor adjustments like removing WGDC, raising boost when on E85, leaning out AFR in certain situations, etc. And the aggressive flash maps all require meth or CPI. JB4 makes it all easy regardless of what flash you want to run.