I am debating on what upper to go with, I like both but I'm not sure if the 1.2 inch difference will be anything noticeable in terms of knockdown. I also don't know with 100% certainty if a permanently fixed flash hider would bother me or not. I am however 100% sure I want a bayonet, so it's 14.7 carbine or 16" middy. Also, light or normal profile barrel? I know that the thicker barrels dissipate heat better, but is the extra weight worth it? This AR-15 will be my go to gun. I want it to be fairly lightweight, but not feel like a toy. I want it to be for anything from HD to SHTF and everything in between. And it likely will be the only AR I ever own, suggestions?