Both. My way of thinking is very much like Izaya's, and I'm more aggressive than I'd like to be (so much so that I've scared people off).

This was pretty difficult. Like Shizuo, I once had severe anger issues, and people could get seriously hurt if and when I snapped (though with words, as I'm not very strong), and I'm also rather introverted. Despite that, I enjoy watching people be miserable, I nickname people, I'm a bit bitchy, I love sarcasm, I lie a lot, and I only have a few friends - but God help you if you mess with them. So, I'd say I'm more like Izaya.

That'll slow ya down, ya twitchy hooligan!

This was hard!
I kinda have little traits out of both really....I have anger issues which can make me super violent, and then again, sometimes i'm more like Izaya....
Idk, I'm more like Izaya when I'm chill, but when I'm angry, it's Shizuo, so.....

Uhh, I don't know! I have traits of them both.
Though I'm not exactly like either of them, I rarely get angry and am more happy, so yeah...

Both traits. I call people by nicknames,the only thing I relate myself on Iza-nii.
Violent on the outside,kind-hearted in the inside.

I agree with everyone else, that was difficult .-.

I’m almost exactly like a less twisted version of Izaya.