Batshit sometimes. Moon Knight is crazy as shit and vicious to boot, yet lucid. Spector is even more vicious and while he found his breaking point eventually did some messed up shit as a merc and without the (screwed up) moral compass of the Knight. Mr Knight seems pretty with it at least in the appearances where he matters (mostly Ellis) but thinking he is in control probably shows him to be profoundly disturbed. Steven Grant is somewhat with it if kind of paper thin but then again in some ways he is tasked with being the mediator and everything working usually hinges on him so he must actually be pretty strong. Lockley on the other hand is pretty sane beyond some of his questionable decisions about who he chooses as helpers (Crowley, Gloria's Boys).
Point being he is not crazy with a bunch of personas, he actually has multiple personality's that are unique individuals with their own set of attributes, strengths and flaws, and level on the crazy-o-meter.
So best answer, Batshit, sometimes.