I've been to Nellie's two more times since my first visit in July, and I have come to the conclusion that I just dont think it's all that. This is largely due to the way I like to eat (I'm not much of a carb-loader), but it's also about execution and lack of flavor. I am a Southerner and this is not like any Southern food anyone in my family has ever made.
As alluded to, most of the menu items are heavy on carbs - biscuits, potatoes, grits, green bean casserole, etc. so understand that these will be your choices as it is typical of the genre of cuisine. There are some menu items that are lighter though. I ordered roasted white meat chicken, and it was flavorless and overcooked to the thready stage, and must of come from the midget chicken farm as the portion was so small.
What I give both stars credit for is that the staff is just excellent. Everyone is always so friendly and welcoming. The servers DO exude Southern hospitality, and are excellent ambassadors for the business.