can't say i have any input to offer for the diy pnp, is it not a smartly box mega-squirt with a fancy plug, only down side, they don't seem keen using water tight enclosures like most other aftermarket ecu .
did run megasquirt on a gtfour st185 ver 1 with msextra code 0249 back in 2006 all da way to ms2 running later msextra code on gt4 st205 .
the early system had a few teething problems with dual VR setup but did make use running oem hardware. ran good, made strong power, great drive-ability for a cheap diy ecu. easy to map exceallant functions very easy to customize to fit any setup. deffo value for bang.
ms3 pro is out shortly, which offers many new features like onboard logging etc.