One of the problems with forums is that, while most everyone is more than happy to help, you will run into a few brand fanatics. You will read everything from (insert brand here) is the pinnacle of AR reliability and performance to (again, insert brand here) is junk. Every AR manufacturer has produced a fine rifle and the occasional lemon. It's the same with other products, and guns are no different. I come from a gun family and have owned guns my whole life, but I've only been in the AR camp for a few years. I got the bug, just like you and, just like you, I started doing research. At the end of the day, I was able to gather some useful information, but I also became overwhelmed by the amount of information and the huge discrepancy in opinions. So, with that said, here's my advise to you. Go to the store and buy one. Rock River has a solid reputation among most AR folks, so you won't regret the purchase. If you find another AR, say a Bushmaster or S&W at a better price, get that one instead. My point is that the AR platform is so modular that your really don't have to worry about your first AR and getting just the right one. No matter what you buy, you will find that the parts are so interchangeable that what you find you like, you simply buy that part and swap it out. If you buy one with an A2 stock and want a collapsible one, swap it out. If you buy one with the 16 inch barrel and decide you prefer the 18 inch stainless, swap it out. With the AR you have far more flexibility than with other firearms. So again, don't worry about the first purchase, any "mistake" you make can be easily rectified.
However, with that said, whatever brand you get, I do recommend getting one that will shoot .223 and 5.56. Also, clean and lube before you shoot and confirm it has the proper staking.
