how hard is the switch to MS2?
 

If I just dropped the chip into my MS1 V3, will I have to change any of the wiring mods? This settings seem somewhat similar, shouldn't be too bad to do that part. The larger tables and a actual PID closed loop boost control loop are so appealing...

All of the wiring mods need to be changed.

Firstly RTFM
MS2/Extra Manual Index

For the ignition you need to build the following circuits
MS2-Extra Miata 4g63 Manual

The spark output mods shouldn't need to be changed....it's the tach input that needs to be modified...then performing the regular mods/software updates to accept the ms-II daughterboard.

The outputs come from different pins on the MSII though don't they?

its an output, it can go anywhere. They suggest IGN and spare4, don't see why you can't use IGN and IAC2A like normal....we don't need to use the stepper IAC control.

Ahh gotcha, I was confusing myself.

I do want to move to MSII & full sequential as soon as I get the money :)