I'm considering purchasing an AR-style Rifle (or Pistol) in the near future, and being that I'm primarily a handgun guy, I'm hoping to get some input from those of you who are knowledgeable in the ways of the mighty AR. First let me say, I'm considering this purchase for two reasons; primarily for use at the range, but also as a home defense weapon as well. I've been looking at models from Bushmaster, Rock River, DPMS, and Olympic Arms; I'm not sure which I'll choose, but I must say, I'm leaning in Rock River's direction. My first question is- when considering a purchase such as this, what caliber do most of you feel is more practical, .223 or 9mm? I could use the 9mm at the range where I currently shoot (I think), but choosing the .223 would definitely necessitate a move to another range, although that's not a major issue. Second, do you feel the AR Pistols are worthy of consideration, or should I stick to the Rifles? Although the prices of Rifles and Pistols are somewhat comparable, at this point I'm leaning in the Rifle direction... but darn, those Pistols sure do look interesting. Your input is greatly appreciated in advance.