I own a Safe Keeper 2 (the older AUS 8 version) and this a absolute recommendable, currently the best factory-made push dagger!
The Safe Keeper is highly efficient for self-defense. The T-handle guarantees a safe grip and enables a high-potential push power. The relatively broad blade is ideal for deep slashing. Furthermore the Safe Keeper 2 has the advantage of a fixed blade (no lock problems, low weight and more stability) and is approximately compact as a folder. Both edges of my Safe Keeper were razor sharp and the Concealex sheath is well suited for IWB and belt carry.
My sole complaint relates to the handle material, I wish CS would use a more sturdy material than Kraton.