I almost refuse to believe that you guys are recommending a 5.5" OAL knife with a 2.5" blade, and no handle scales for self defense.
You know, when people ask for advice on a blade their life might depend on, it wouldn't hurt to look past the brand name, and actually take a look at the knives.
Of the two, the MOD, definitely. It actually has a handle (not to mention one that you can get all your fingers on), and a longer blade (beware your local laws, IIRC is 3.8").
The AS is a heavy duty 3-finger neck knife.
The Razorback is designed for self defense.
There are no similarities between these knives, or their intended purposes.