Which beginner ad monetization network should I use?

I've heard some pretty bad feedback about Ezoic. Ads are slow, slowing pages down, messing up formatting, etc.

They've been pitching me for a while, and shared a couple of case-studies. I checked out one of the case-study sites and it was hideous. Maybe their ads generated more revenue for the site owner, but the site seemed so shady that it completely discredited Ezoic for me.

I suspect they work well for some, but I wouldn't consider them based on the above.

Here's a few others you could take a look at.

http://sortable.com/
https://nicherev.com/
https://www.infolinks.com/
SOVRN
Primis