The blade is amazingly sharp (I've never seen a sharper serrated blade) and a serrated edge makes it much quicker cut on a line under tension. The marlinspike is flat and its open design doubles as a shackle key. The flat marlinspike is easier to push into a tight knot than a rounded one, and enables you to use a twisting motion to lever the knot apart. Much better than round. The other tools are nice to have also.