JD, good info. Except, chrome lined isn't a bad thing either. For alot of the newer folks to the field of firearms or just to AR's, chrome lining could be a blessing of sorts, too.
True, if you were to get down to the business of building a tack driver for competition target shooting, I would definitely leave the chrome lining off the shopping list. The main reason being that we haven't developed a method, or at least a cost effective method of applying chrome lining to the bore that is consistent and equal thickness all around. How far off is it? Not enough to really worry about for most of the shooting population. Still there are those that feel that the fact that it isn't concentric in the bore will effect their shooting enough to make them stay away from chrome lining. I think it's the extra $40-50 more than anything
For newer shooters, I find that the chrome lining is more of a blessing, in that it eases maintenance and cleaning of their new firearm and offers a bit more protection to the bore and chamber. No, it isn't a necessity, nor is it a bad thing either. For target or varmint guns, I do prefer a non-chromed line barrel or a stainless steel one. For tactical application or home defense, either is acceptable, but if it is something that will see alot of rounds - I will go with chrome, just for the easier cleaning. No, I'm not lazy at maintenance either, as anyone in my house will attest to. I'm a fanatic at keeping my 'tools' in working order and where they belong.
So to Johnsteele, you are getting alot of great info here, and as some of the other members will tell you, helpful, too. Good luck on your new AR.