I'm about 230 and I still land gaps with 10+ feet drops while riding anti-rocker.... so yeah, they will hold you up... you might crack your frame so I suggest riding flat... but then again, it might be hard to ride flat if you're just beginning.
One month after I posted this I got myself a pair for 300$. Definitely a great buy if you live near a skatepark, like I do. So much fun, and a great way to pass the time until snow hits the ground again.