I have read and read, and as I read more I get further lost, 1:7 or 1:8, crome lined barrel or stainless barrel, forged or machined lower..... ARFcom hates M4 and vice versa. Ok here is what I really want to know, I am looking for a 16" mid length with a full quad rail. I have been looking at DD, LMT, Spikes, and BCM. Would I be ok with any of these manufacturers and what could be the down sides to any of these manufacturers?