Hello Everyone.. and thanks in advance for not picking on the newb here too much if I ask some basic questions. 
I've gone and placed my order for the M&P 15 sport tonight and pick it up on Thursday and am very excited. The guys at the shop were all very knowledgeable and helpful. I didn't get robbed on the price, I did my online comparisons before going in.
One thing I want to be sure of is which caliber is best to run through it. I noticed many models state both 5.56/.223 whereas this one only states 5.56. The guys at the shop assured me I can run both. Do you run both? Which do you prefer? What difference do you notice?
Please understand, this is the first rifle I have ever purchased.
I've always been partial to handguns as rifles have always been larger, heavy and awkward for me.(woman) A friend came over recently and he let me shoot his AR and I loved it and decided I had to have one. I feel I've made a good choice with this model and am planning to mod it just a little in the future. Rail, Light, Grips are my basic plans.
Thanks for any input!

I've gone and placed my order for the M&P 15 sport tonight and pick it up on Thursday and am very excited. The guys at the shop were all very knowledgeable and helpful. I didn't get robbed on the price, I did my online comparisons before going in.
One thing I want to be sure of is which caliber is best to run through it. I noticed many models state both 5.56/.223 whereas this one only states 5.56. The guys at the shop assured me I can run both. Do you run both? Which do you prefer? What difference do you notice?
Please understand, this is the first rifle I have ever purchased.
I've always been partial to handguns as rifles have always been larger, heavy and awkward for me.(woman) A friend came over recently and he let me shoot his AR and I loved it and decided I had to have one. I feel I've made a good choice with this model and am planning to mod it just a little in the future. Rail, Light, Grips are my basic plans.
Thanks for any input!