Yup, I've done this before, aswell. I do like to use planes, for quite the reasons already stated. You can attach most displacement shaders to a plane and use its data as the 'terrain' data.
An alpine fractal doesn't work, however.
To really speed up an alpine scape, use the heightfield shader's 'shader' parameter to generate your terrain from an alpine fractal, then simply save the .ter and use that. You'll be surprised at how much this speeds things up. As long as you don't need a massively distant shot, of course. And you can re-use the same terrain over and over, too.
