A lot of the ads were freezing my browser as well (it didn't matter if I was using firefox or chrome). I usually had to restart after a minute or so, and sometimes nexus pages flat out refused to load. Luckily $2 is something I can easily afford (and something I wish more sites offered), so I recently just paid to turn the ads off and everything has worked fine since. Edit: after looking at some of the other comments, I'd like to second the option to turn the ads back on as a way to further support the site. I'd happily do that if some of the malicious ads were rooted out.
