so M-lok seems to be dominating right now. What makes it better than keymod?
Which system has a better selection of accessories for it that connect directly, rather than using a standard rail section AND the accessory?
Mlok is new and has Magpul marketing behind it. That's about the sum of it. Keymod was released under Vltor with practically no marketing and no single company pushing it. Some argue that mlok has a greater shear strength, and I can see how that would be true. But I'm not hanging from a helo skid by my free float rail, so whatever. Others say mlok is cheaper to machine. I don't really see much price difference from manufacturers making both systems. So the manufacturers increased margin doesn't do a dang thing for me. Some people don't like how keymod looks. I could care less about aesthetics.
I waited a couple of years to see how keymod would be accepted. Shortly before mlok was announced, I got into keymod. I've been very happy with it and see no need to change. It works very well and just about every accessory you can imagine is made for KM. It's simple, lightweight and secure.
Piece for piece, mlok accessories are heavier and I don't care for the big backer nuts. In one case, an upper I assembled had an issue with this. The rail was a really thin profile and the barrel was a heavy profile. The backer nut was making contact with the barrel.
But I think they work equally well. The bottom line is that the industry made keymod what it is today, by accepting the concept and supporting it through adapting old tech over to KM.
MLOK is currently popular because it works just as well and few companies market as well as Magpul.
I love how they make keymod seems so cutting edge and new. Keymod has been around forever.
That's an oversimplification of a well engineered design.