Two totally different things! Grits are savory (unless you're from the north and put sugar on them) and oatmeal is sweet - with all the brown sugar I put on it
ASM - have you had the steel cut oatmeal? It's my favorite. I've cooked them overnight in a crockpot if I have guests but apparently Trader Joes sells them frozen and ready to thaw and eat. IMO, better than even the slow cooking rolled oats.