Yea. I tried them yesterday after reverse band deads and zerchers. My erectors are more sore than they usually are after that stuff. If I make a fist, my forearms are sore so it nailed my grip too.
The highest I went up to was 185. It was so hard to grip I actually had to try the hook grip for the first time. I was able to get it with both my left and right hands. I tried 225, but no go. Felt like my thumb was gonna rip off.
I'd like to get crazy stong on these one day, like 3 plates, and just walk into a gym during rush hour and freak everyone out with them. hehe