One of my team mates, our resident former Spetsnaz Czech, ran across some other Czechs here in Baghdad who are looking after some of their dignitaries. They mentioned that they prefer their Cz-58 rifles, since the 5.56 was not good enough, especially in urban areas.
They also only shoot black tip AP ammo, since it will go through most body armor found here, and also armored SUVs. They mentioned that they have tested it on vehicles, and it does penetrate. They are not too concerned about what the round AP round will do to humans, since it is a 7.62x39. They want to be able to shoot into vehicles and urban structures.
I am required to carry an M4, but I would not hesitate to trade it in for the CZ.
I think the CZ 58 is elegantly simple. Its light weight and compactness makes it a perfect SHTF weapon. It feels much better in my hands than the AK does.