Had a pair of JJs the first year they went rockered (current shape) and they exploded in 4 directions when i landed on a rock (granted it was a rock) but with K2 hellbents, Ninthwards and Batallas I have stomped rocks with merely scratches or in some cases nothing at all. I'd say they're are a lot better skis on the market if you can try as many skis as possible until you find something you like. (if that was the JJ then go for it)
anyway personally i didn't like the way they skied and sold the pair i got through insurance before even mounting them.