I have last year's Chronics, the ones without rocker. Really fun, stable skis. I'd rate the flex as medium-stiff, but especially now that they have some rocker you can definitely butter them.
I ski 95% park on them, mounted -2, wouldn't have it any other way. My friend has this year's rockered Chronics, mounted -1.5 and he's very happy with the mounting spot as well.