I agree that Chaos guards make sense, if you don't have a retainer.
In my case, I have a retainer. I purchased a clone of UTG's guards on Amazon for $30 delivered. I am very impressed with the quality. I am replacing plastic ATI guards. I have a DPH rail and a Mepro 21 sight. I want the forend rails to hold a flip up front sight and a Magpul AFG2. So, there was no need to spend the money on high end guards.
Anyways, my Dinzag retainer is designed for a handguard with a recessed interface(not a great description, but the best I can do). The new guards are flat on the front.
Before I take a dremel to the retainer, does anyone have a elegant solution to getting the two to work together?