I don't see what benefit there is to foundling and shooting some particular variant to rule it out. It is just another M-4gery, and will feel and shoot about like every other basic black rifle out there. The differences between the various makes and models are in the details... like materials, testing, twist rate, and other specs. Reliability cannot be reliably assessed by holding a gun and putting a couple mags through it. Short of buying several test models of various ARs and scientifically testing them to failure with terms of thousands of rounds, the best guarantee of quality and reliability is to buy rifles with certain minimum standards of materials and testing. When you have a choice between two rifles, with one having top quality materials and testing and the other not, and the price isn't much different, It's pretty clear to me that the one is better for the money than the other.
