I went into the Dark Zone for the first time at level 12 to see what it's about. I started a firefight with 5 elites (gold health bars) that I was managing decently with some kiting and use of my smart bombs. It looked like I might pull through but it was gonna be close. Suddenly I got flooded by at least ten strong (purple health bar) dudes and just got shredded.
Not gonna bother with DZ again until I hit the end game and then only if I can find some people to play with.
Yeah, at 30 you'll have not just the purple and yellow guys, but also a group or three of try hards ganking you while you're shooting at the AI. lol.