Hollow, schmollow. I have a special router bit that's 4mm wide and shaped like a >. It cuts a nice little v-shaped groove into the "edge" of the blade so I get two really sharp edges. That's the equivalent of about a 6mm hollow.
The other day I dropped off my skates at Duke's in Toronto for a Body Profile sharpening. After talking it over with the guy, I got a 28' radius and 2mm higher in the back. Today I picked them up and went to Canlan for pickup hockey. Oh, these skates are nice now.

So nice that while playing, I didn't even notice them. I just moved and skated and did what I wanted, and the skates never got in the way.