I actually own the Imperia's in black and have posted on a few blogs that I actually find them very uncomfortable! I've tried a bunch of tactics to make them comfy but to no avail and it breaks my heart because it's one of the few items of Kate's that I could actually afford! So imagine my glee when I spotted these replikates at Le Chateau, a store of which I own several pairs from and are always comfortable.
These shoes are amazing! I find they have a slight padded sole that adds more support to the ball of the feet and the wedge is a comfortable height. I wear a tiny size US 5 and ordered that size and it fits like a dream. I would say they are true to size. They're so amazing, I might order the black ones too!
I've attached some photos of the shoes on my feet as well as beside the Imperias for a true comparison (really hard to tell at a glance!)