Not working for Dyn, but a another Civ contractor. I have run across several of their guys. Missions run from class-room "This is how you handcuff a guy" stuff to....slighty riskier operations.
Right now I am involed in Physical Security and VIP Protection and so far, the Dyn guys I have worked with have been top-notch, no-bullshit.
Depending on how you are tasked, you may end-up working with SOCOM-types, either active guys or guys that are working for the same or a different contractor. All are VERY professional and skilled operators. I came from civvie LE, though I did have previous military XP. Working with them is easy as cake, as long as you aren't a moron. Morons go home, in a bag or on plane. They expect you to be a shooter. If you aren't, you wont make it anywhere near the sandbox.
From what I have heard, DC pay varies based the 'threat' level you are expected to encounter. I can say that I am NOT in classroom, and I am making more than 120K.
Definately the wild west. Gunfire w/in AO is nightly. Mortars, RPGs...you name it. I'm not talking about a couple of blocks away either...I'm talking across the street. I sleep in my in my body armor, only thing that comes out is the rifleplates. Otherwise it's like tryin to sleep on top of a phone book.
The real issue is a lack of armored vehicles. As in, lack of. All those white pickups? Might as well drive around in cardboard.