A friend of mine works for Safi Airways in Kabul and it's fair to say that they are the best of the civilian airlines operating in Afghanistan.
Having said that, in Feb this year the hotel the crew stay in got attacked by Taliban suicide bombers. Some crew members were very seriously injured, one almost losing his life.
Safi Airways is run by Germans. All the flight deck and a lot of the cabin crew are from North America and Europe, therefore the standard is allegedly of a reasonable level. However, most of Kam Air are not what you would describe as being FAA, JAA or even ICAO approved.
My friend did return and I haven't heard from him for a few weeks. But judging from what he's told me (No reason to doubt him), if you're going to venture to Afghanistan then don't go anywhere other than Safi. The other Airlines are pretty bad.