I recently got a 2016 MacBook Pro and just performed my first real test with FCPX and Compressor on it. It completely destroys my 2010 Mac Pro in this area, but I would still like a little bit more power. What I am doing, is taking a 2-hour h.264 video, cutting it up a bit, and rendering it out. My laptop, for every minute of source footage, takes a minute to render. So mine took two hours to render that video. My 2010 Mac Pro takes around 4 hours, so there definitely is an improvement!