Recent posts have led me to wonder what is the difference between the two lines. Both comprise a variety of dissimilar models( as opposed to, say, a frogman, which is based on one or a few sets of features) Both have tiitanium cases? Also the mrg1200 and gs300 share basiically the same module. Are there other cases where that is true for a gs and a mrg? Finially, do all these watches have single production runs?