I have a set of M33s which is the 2-rail "carbine only" version of the M44, but I chose them only after much consideration and prior experience with them. I sold the last pair I had because I found much better products to use in their place, but this time all I wanted was a place for a vertical grip on a Bushmaster superlight, while keeping the appearance of regular handguards (KISS principle to some extent).
They are FAR from mil-spec rails. I have a hard time getting a LOT of stuff to fit. Again, I don't care because I made this choice after experience with these and other rail systems and I recognize that the others are much better, but these just happen to be what I wanted for this one particular, unique application.
The M44 doesn't look like regular handguards, so that doesn't help any. In fact, they're fairly UGLY if that matters at all.
BUT what they really are is NOT WORTH IT because you can get MUCH better quality pieces from MI or YHM for roughly the SAME PRICE! Those rails will be in spec (more or less) and better quality by leaps and bounds. You'll definitely find more things will fit than I can on my M33.
Bottom line, I had specific criteria other than quality of the rail itself when I made my choice. Otherwise, look elsewhere for better quality but similarly priced options. Check board vendors in the EE for super deals on either the Midwest Industries or Yankee Hill Machine rails.
Bright Flashlights carries YHM rifle length railed forends for $145
BravoCompany USA carries MI rifle length railed handguards for $179
Either of those products WILL be leaps and bounds better than the Fobus M44 handguards.
You WILL thank me later.