GUI textures vs. planes for menu

Maybe I’m not searching with the right keywords, but could someone point me to some documentation or explain the difference between GUI textures and image planes? Im making a menu for iOS and have some 2d images that I want to display. What’s the preferred method to do so in terms of performance and quality pixel perfect images? It’s very difficult for me position GUI textures exactly how I want them…

To make it simple and short: GUI is far too expensive on mobile (especially iOS). Use textures and quad.