I'm helping out my fellow Hero owners by taking time to write this review because there are *no* reviews for any Hero cases on Amazon.
I bought this solely based on the pictures and because it was a gel type case. It fits tightly around the phone. There is a small lip around the top edge so it holds the phone in the case. There is no way it will slip out of the case. It's a tough transparent gel/rubbery material. The Hero's chin fits perfectly too, the case is actually designed with the chin shape.It does add a tiny bit of bulk, but 1mm or thereabouts is not too bad.All the cutouts are there too.
One bad point though, the cutout for the volume button is weird, it's the right shape but it just doesn't seem right. Would have been better if it wasn't there. Oh and you might have some trouble if your headphones have a fatter plastic bit above the pin, the case might stop the pin going in all the way.
Still, I think it's the best case out. I did drop my phone recently and it worked as a case should (no damage).