At Niligiris, Besant Nagar, Chennai the staff is heavily biased towards white-skinned foreigners (well, lot of Indians are, unfortunately). Once I was asked to step aside because they wanted a foreigner to check out before me. When I started making noise, the manager came but ignored my objection! That was the last time I visited that shop.
At Nilgiris, Gokulam, Mysore I found product quality to be poor. Once I bought some red rajma and when I soaked them in water, after two hours the water became red and the rajma became regular brown rajma! In some occassions I found them overcharging when they manually enter price of the items. The staff are least knowledgeable about the products they have - you ask a question and they draw a blank.
Surely, there are better options these days. I avoid Nilgiris and try More or Reliance Fresh.