They're difficult to modify (not use) because of an RS-Autosport-designed daughtercard that's mounted on the underside of the main circuit board. If you're not experienced with circuits and soldering, it's difficult to remove and/or modify. Furthermore, it's nearly impossible to upgrade to MS-II since the option circuits will need to be re-configured for the new processor's pin assignment. You'll need to either purchase RS-Autosport's upgrade kit (if they're available) or prepare yourself for a lengthy and difficult process.
