Our friend and interface designer Abhishek Nandakumar writes about the value of designing with prototypes instead of static mockups. He uses the example of Google Maps to demonstrate how working prototypes can often reveal counter-intuitive improvements in an interface, like increasing the number of clicks:

Most time is spent navigating and scanning through the interface, but if the interface and the path to your eventual goal are both clear, clicks might not matter, because you’ve reduced a majority of the cognitive load associated with scanning.

We’ve felt the same for a long time, and hence prefer designing our sites in the browser as often as we can.