ive seen many threads over the net discuss the merits of x.264 vs h.264 encoding.
as the mainconcpets h.264 is fairly embedded into the adobe suite, would it still be a better encoding choice than x.264?
my primary concern is speed and then quality.

To use x264 one usually has to output to an intermediate codec and then the speed benefits of x264 are lessened. If you can frameserve to x264 and the overhead is reasonable then x264 might be more competitive. Usually one goes to x264 when they are doing low bitrate or want every last ounce of quality.

afaik you can run an x.264 graphical ui like megui directly from ppro so you dont have to do an intermediate encode