Would it be worth starting a thread with some information on the various types of piggy-back ECU, possibly that could be a sticky ? It's something that's often asked about on here. I'm assuming there isn't an old thread like this already.
I'm thinking of something like the exhaust sticky that we already have, e.g. TTE black box, HKS FCD/VPRO/etc, Greddy, Unichip, etc. Pros and cons of each (e.g. some can control fuel injectors and some can't ?), reliability (bad for TTE black box ?), rough cost, ease of config/mapping, suitability for supercharger/turbo, etc, etc.