DaetrinWhich Merrill's are you inquiring about? From a brand standpoint, Adidas is an athletic brand and they design shoes for "outdoor athletes". I think that is a big differentiator between the two brands and the respective muse to which they design their shoes for.
DaetrinAt a glance, I'd say the key differences to the Moab 2 would be:
Continental Rubber (I am obviously biased, but I find Conti to be the softest & grippiest rubber around), we mimic tred from their mountain biking tires
Upper Fabric - We used a closed ripstop mesh upper... Compared to the moab, it will be a lower profile and most likely keep a bit more sand out of your shoes
Quick-Lace - Kevlar sliding lace closure system (can be swapped out for regular lace)