I'm looking for my first AR15 rifle, and I'm leaning towards a Colt LE6920. I see there are multiple versions of this rifle, including a SOCOM version. I don't know much about AR15 rifles, but I was recommend a Colt LE6920 by friends. Any comments or recommendation on the best one to get? Finally, how does this compare to Ruger or S&W or Bushmaster AR15? The purpose will be home defense and range shooting.