I'm a little disappointed by the opencl/cuda support.
I was hoping they'd be fully integrated with native algorithms in mma. Instead you need to change your code to call CUDAfft[] or whatnot. It should just choose the right fft to use, or supply a checkbox in preferences.
Mathematica programming language is somewhat symbolic, like Lisp; so you could just "rewrite" your expressions to use CUDAfft[] or whatever very easily.
