I love my polymer because it follows closely the Masada concept- really like the feel almost FAL like!,the internal tracks for the MOE rail screws shows forethought on someones part! the current aluminum lacks detail to me -not enough cooling holes, was not relief cut for mil. spec. knights covers, no 1/4 x 20 mounting holes in the rails either just "blocky" looking! the newest rail handgaurd being shown looks much better IMHO and REALLY like the rounded mounting studs for faster on/off times, we will see....