C# making an optimized UI

Is it a good idea to make a UI that is made of textured sprites and is visible with a second superposed camera that only sees UI? Or maybe remove the system with 2 cameras and try to only use one camera, but still with only textured sprites? I love to have my interface layout in front of me when I work with it.

I’ve been extremely happy with NGUI (available in the asset store). It uses the additional camera approach, and you can see and manipulate all of your UI elements during design time. It also has performance benefits (such as drawing much of the UI in a single draw call, depending on your layout).

Not everyone can afford to spend extra money, but I thought I would mention this alternative anyway.