I have both a Valentini and a Sharpnose Fiji Puffer and while the Valentini leaves everything but hermits and snails alone, the Fiji chomps on most LPS and SPS. The only thing he doesn't bother are my Blasto's, 'Shrooms, Ricordia, Plate Coral, Encrusting Gorgonian and another coral I forget the name of... kind of looks like an open brain and is colored like a watermelon...
Right now, the latest victim of Blue, the Fiji, is the Pulsating Xenia. Grrrr.
We had some Acropora but he kept chomping on the tips, so we took them out to stop any further damage.
He's such a PIG!
Anyway, yes, it is hit-or-miss. Like crazedpuffer said, try some cheap things and see how he reacts.