i am going to have to disagree with your second-hand assessment, based on my first-hand experience with the HAYLE Rail. The only "fussy" part of the Rail's installation or removal is the requirement to loosen and tighten 4x Grub Screws which are loosened for Rail removal and tightened to cinch the Rail down firmly to the shotgun during assembly. While a single tool is required for the Rail removal and installation, the process remains incredibly fast and simple.
The HAYLE Rail may not be the perfect MLOK Layout, etc, but it works well enough to mount flashlights, IR Projectors,, lasers, a VFG, and so forth to the front of your Benelli M4. The price was pretty reasonable and the quality of the machining is very good. Lacking other options for an M4 Railed Handguard, the HAYLE Rail works pretty well!