What do you guys like?  The MR556 comes with the HKey rail which absolutely sucks balls.  

https://hkparts.net/product/hk-416-mr556-14-modular-rail-system-mrs-black-p17342.htm

Right now I have the MI hk416 9" rail and it is much better.  However it is definitely a strange shape.   Much taller than wide.  The bottom sticks out noticeably.  

How does the G rail compare in profile?  

The RAHG?  

What do you guys like?

Pics would be appreciated.

Thanks!

G rail is the best rail. It's the most comfortable of all the 416 and even m4 rails.

G rail is good, but also heavy, on an already heavy gun.  Strike Industries made a lightweight SLICK handguard, but it’s been discontinued?

I have had the Geissele, the RAHG, and factory rails.  All of them have some compromises, and there's no altering weight issues inherent to the 416.  It is always going to be heavy.  On my 10.4 I just switched from the Geissele to a Maxim Defense handguard, and so far I like it better. Getting as slim a profile as an AR isn't something practical for the 416 as there's only a limited amount of things you can do since the op rod takes up the space it takes.  What I like about the Maxim is that it's well made, sturdy, and they added as much length on the bottom as they could add and still allow for room for a Surefire suppressor's mounting collar (short scoop version).  For my own needs and preferences, it fits the bill.

I am 400 miles away from my own gun currently, but here's some pics that ran on Soldier Systems: Maxim HK416  and The Firearm Blog: Maxim HK416

The Lancer CF rail is the best rail imo. It is the most ergonomic and lightest option I have used.

Strike and MidWest have horrible extrusion profiles where the lower 6 o clock rail is dropped down.

What is a “horrible extrusion profile” and what is it’s effect on the rail?

How is the cross section?  Is the G rail much taller than wide? Does the bottom rail really drop down low on it? That is my issue with teh MI rail.  Dang 6 o'clock rail sticks down too far.

That looks good but I have never heard of it until now.  How durable do you think it is?

That is my problem with the MI rail....bottom rail sticks out like an after thought.   It creates a gap in my grip that is annoying.

The cross section design

Lancer has zero drop on the bottom. Pretty much a octagon with rounded edges and a 12 o clock rail. VERY comfortable, not mention insanely light compared to the other HK416 rails

I had the G rail but went back to the HK quad rail.  The G rail was nice visually, but you still had to mount Picatinny sections on it to make anything work, unless you wanted to direct mount stuff which would be a pain if you wanted to pull a light off to throw on another weapon.  

I like the quad rail...it’s iconic and no heavier than the G rail I learned.

I'm a fan of the quad rail... just looks and feels right on a 416. I use ladder rail covers on mine so the feel isn't so cheese grater-ish though.