The stock one is perfectly fine until you go to hang stuff off it, like a weapon light. It has what I believe to be a non-standard for AR threaded delta ring. Concerned that an aftermarket handguard might not fit, I got a "Rogers 'Tri-Rail" attachment that fits around the handguard at the front behind the front sight, but its placement is right where my support hand wants to naturally rest and not comfortable to hold.

The Tri-Rail assembled:




Top & bottom handguards, removed:



Delta ring and upper receiver:



It goes together easily, but needs a strap wrench wrapped around it to remove it. There is a great deal of friction between the parts.

This is more to satisfy my curiosity than a true priority. I have a 5.7x28-caliber LC Carbine for actual inside the home defense. Much lighter and shorter, and nobody is going to want to stand in front of a 40-grain ballistic-tip bullet going just shy of 2200 f/s. (I chronographed it myself.) It has all manner of M-LOK holes in the handguard that I can mount a light to.