I ordered the Survival version 81 which comes with the saw back unlike the 78 which is a flat back. It also comes with a belt sheath and boot sheath (optional)
The first video below talks about all the features and the second video is one in an 8 part series where the owner puts the knife through a vigorous "destruction" test and he eventually brakes the blade in two but not after much punishment.
After reviewing the Glock M78 Field knife and M81 Survival Knife it is hard to compete with this amazing blade. If you can find one I would definitely buy one. I believe you can order them right from Glocks outdoor accessories page