Allied MCV
The tactical benefits of adopting the MCV system have been argued extensively by Mathers, O'Donnell, and others (For a complete historical analysis, see Tactical Engineering: A Review in issue 468 of Modern Warfare), and little need be added here. It is worth noting that, while many focus on the MCV's use of Standardized Production Assembly Modules (SPAMs) for building construction, in fact the technology of fabricating a wide variety of weapon systems from a single universal component is not new. Traditional production structures (War Factories, Air Fields, and the like) have been using SPAMs for over a decade: the progenitor series of on-site, quick-assembly modules - the tank SPAM - effectively redefined mobile warfare with the first effective medium tank designed to be assembled on the battlefield. A more revolutionary technological aspect of the MCV system is Virtually Operated Industrial Production (VOIP), a system that allows MCVs to remotely enable the production of advanced technology weapons. This same system can now also be found in the Allied Prospector.
Soviet MCV
The world got its first view of the new Soviet Mobile Construction Vehicle in the aftermath ofa devastating earthquake near the small hamlet of Smedznegorsk, Ukraine. Aid organizations and media crews broadcast images of an immense vehicle and its incongruously small crew distributing prefabricated building components to the residents of Smedznegorsk. With thousands left homeless and quickly-darkening clouds on the horizon heralding the approach of a massive ice storm, initial coverage of the government aid effort began suggesting that it may have been too little, too late. Cameras continued rolling in front of speechless reporters as, moments later, a miniature city sprung to life from the wreckage. The structures themselves were grey, drab, and cookie-cutter, but they were warm and dry, a welcome replacement for the piles of rubble that were formerly homes and businesses.
Imperial MCV
While the stolen technology undoubtedly aided the research efforts of the Imperial MCV program, their vehicle is anything but an exact copy of the Allied and Russian versions. Instead, the Japanese engineers used the acquired designs as a springboard for their own ideas, coming up with a system that is well-specialized for their own military doctrines, and applying the same creativity and attention to detail that Imperial spies used to gather the information in the first place.
You can read the full articles, along with short videos of these units in action here, here, and here, at Command&Conquer.com.