New M4 Chart by rob_s
Ok, so the new chart by rob_s at m4carbine and tacticalyellowvisor.net is a work in progress but is now available. I've posted a link below to the thread on m4c.
This one will have a good bit more info than the last.
NEW Comparison Chart of Commercial M4 Pattern Carbines - M4Carbine.net Forums
EDIT - I'm adding the link to the thread that includes the original chart. There's an in depth explanation of features in that chart eventhough the manufacturers have been removed. The original is still floating around out there if you know where to look.
Sticky done been stuck! Thanks for posting.