okay.
from my experience with ECUs, i can say the MoTeC is a wonderful thing.
datalogging cross referencing (ie checking braking points versus throttle positions trackside to see where you were quicker/slower into corners), lamba probe setups, ability to run CDi as mentioned by NIS15L, more mapping points than you can poke a stick at and electronic boost control option coming soon all make for a wonderful package....
...for a race car.
it's overkill on the street. seriously overkill. you don;t need half that stuff that you're paying for.
an autronic/haltech will give you roughly the same mapping points without all those wonderful datalogging systems.
as will a delco. actually, a delco has MORE mapping points than MoTeC, with the ability to run thermos/elec water pumps, fuel pumps etc etc like any other computer. MILLIONS of dollars (US taxpayers dollars too

) have been spent by GM to perfect this system to be a true "plug and play" system for all GM dealers with Kalmaker software.
the CA18DE/DET computer IS reprogrammable, same as the RB20DET computer.
I would advise you call C-Red Tuning in Welshpool, WA and ask for Glen (Lumpy) Campbell. If this guy can't make your CA get up and boogie, no-one can.
you'd be surprised what you DONT have to buy to make it a very powerful package.