Rice Cereal VS Oatmeal

We had our 4 month check up today. Our Ped said it would be a good time to start rice Cereal. I mentioned all the negative hype to her. She said that Baby does not need any extra nutrients so nutritional value doesn't apply. She also said rice is far more easily digestible and would never recommend Oatmeal as a first food. I trust her 100% so we're starting rice cereal this weekend. My LO is only in the 20 percentile for weight and showing all the signs she is ready for substance. I am just curious to see how many use what??? Maybe, in a month or so we could try the Oatmeal.