The trace is a combo helmet, meaning it can be used for skating and skiing. It has the standard skate comstruction.
I have the HIFI and its such a sick helmet, Its super light and it dosen't look huge.
I don't know anything about the giro, sorry.
Arrrrrg, I spent 1200 on a new setup this year. I knew this was going to happen, FUUUUUUCCK. I guess I'm going to become a hermit and play 360 everyday all day.