I am good enough with them to use if I run out of ammo for my main weapon. But my playstyle is getting headshots all the time. So obviously I will choose a precision weapon over an automatic weapon every time.
I personally prefer the DMR. Not because everyone says it is OP. I have always liked playing more of a marksman type than an assault or heavy weapons player. It just fits my playstyle. Although the SAW changed that a bit, I still start with the DMR.
I played Reach on a four then I didn't play it for several months. Had to change it to two. On Halo 4 I am using two just because that's what I had it set on Reach. Haven't tried making it higher.
When I first used the Railgun I didn't like it because I couldn't hit anything. However after a few tries with it I began to like it. So in my opinion it's a decent weapon.
I like the look of armor with sharp angles which is why I am wearing Wetwork and will change to Venator as soon as I unlock it. As for colors I am currently steel and violet. My colors change periodically because I can't decide what combo I like best