I carried one when I was with the 56th Air Commando Wing (later 56th SOW) in 1967-68. I gave it to a roofer years ago to cut shingles with. Once you wear down the zinc phosphate and thin out the edge some, they will cut. The steel is only hardened to about 54 R to ease sharpening in the field. They are rugged and can be had for about $30 or so. Some outdoorsmen swear by them. A friend of mine (former Marine recon) said it was the preferred knife in his unit. I managed to get a Marine Combat (the preferred knife in my outfit). Jarheads with AF knives, Flyboys with Ka-bars. Go figure.
I like the bigger blade better, but the AFSK is a good knife. For survival, the new Gerber is LMF II is better. I like the Sealpup Elite, too. Some survival experts recommend small knives. I really like the Ontario RAT-7 or the RTAK, but I'm no "expert".