Re: Help with a new gun choice....
Really depends on the type of use you want from the rifle. A stainless 24" tube won't work as well as a 16" light contour for home defense, and that same 16" won't have the velocity to throw bullets farther down range than that 24".
That said, i've had experience with a few "heavier" barreled AR's. My favorite being a Rock River 16" HBAR with an ACOG. The shorter barrel was lighter than a 20" and it was easier to transport and carry. The shorter barrel was plenty stiff and the loss of velocity was not a big deal for my shooting, being inside 300 yards. It was a damn accurate carbine. I've also got a bone stock 20" A2 that I love to shoot. The rifle has a longer sight radius, and it a ball to shoot with irons farther than 300 yards.