My area is kinda small and specific, I would choose ETH simply because of research interest match. Fun fact: CMU don't even have people that matches all my research interests XD. I definitely acknowledge I have my weak points and I am not a perfect candidate, but I couldn't help wishing ETH could be like EPFL and accept more direct PhDs! The competition for DD is crazy.... Well I guess it's not meant to be.
For your situation, both schools are great for machine learning. CMU might be slightly better. Where are you from? If you are not european, US is also better for getting an industry job.