Fenix isn't wrong, but I don't think he's covered all the right ways, either. Psychosis plus stealth (why else would you be wearing ninja tabis?) is really good at alpha striking anything that's even a little bit squishy. You can stun, incapacitate, enrage, or even slow melee types so you don't need to worry about them getting to you; you can alpha the crossbows so they just spend all their time dead; but what you can't always reliably kill are the really tanky ranged sorts (and they've pretty much always exclusively got ARs if they're ranged) and the off-in-some-corner-somewhere rifle snipers. Both of those are high-speed projectiles, so if you tend to alpha soft targets first it could be to your advantage to go High/High. Melee won't get to you, SMGs are no threat at all, and you just keep in mind each fight that if you see somebody with a crossbow, they gotta die the turn you come out of stealth. Then you can LOS things so if there are others somewhere out in the fog of war they have to come running around a corner to get to you, where you've placed an Electrokinetic Imprint or something.
If you play a sloppy game, Low is a really good idea. But if you optimize your pre-combat placement and open with heavy killing shots (and that's what Psychosis is really all about) then you don't have to worry about anything on the low-speed side.
