I have that rack (purchased from Nashbar.) Here's the scoop:

It mounts to the canti studs and the fork crown.
It's about big enough to hold a 6-pack.
The suggested weight limit is 15 pounds and I've had up to 30 pounds on it for short trips (under 3 miles.)
The struts don't really leave much option for mounting w/o canti studs. If you want a front platform rack that will be stable to mount w/o canti studs, check out the Velo-Orange Randonneur front rack. Heavy gauge fork tang and longer struts designed to mount to either eyelet mounts or p-clips at the fork blades. It also has 4 mount eyelets on the platform rail which are perfect for securing a cargo net or mounting headlights out of the way.