i understand the problems with these ecu's, i am from the 200sx and skyline scene so this battling for power is new!!
As my Z is currently standard it 'should' (using should loosly there) be running to the lower end of its paramiters, so it 'should have some headroom for a little easier breathing.
And after hearing lots of my friends systems i am pretty sure its gunna sound
Again it is in the early days but how it has worked in the past is
I take my car in and we look at all the options and dyno the car
The system is then built from scratch using high quality stainless, i then take it away test it, report any faults etc and the system is adjusted until it is perfect then dyno'd
my system will then be taken back off and my friend builds a jig to allow him to make more all exactly the same, making it a direct bolt on, of which ESR, if there is enough intrest will stock the system!
I will say it again this is in the very early stages and not set in concrete