You will understand better once the Lap3 ECU is released and becomes more popular. It will be the same thing that companies like APR provide in an ECU tune - a one-size fits all with a few maps to tailor to some
mods or fuel. But then people might want water/meth injection, some might want to up the boost a little more, some might want to do both of these things. Lap3 isn't going to revise the tune on your ECU based on your needs to accomplish these goals; however, the JB4 will be able to supplement the ECU tune fully to do these things (and provide logging capabilities which is crucial for a lot of people)
Personally I don't see the benefits of the ECU tune
yet on this platform. Quicker shifts and higher launch RPM would be great benefits but we haven't seen any evidence that this can be accomplished. AFR, boost, and timing (which is pretty much most of what is required to make power) is very similar between the ECU logs and JB4 logs that have been posted thus far.