I have no experience with the Eos M. I have a 100D, but haven't taken raw video with it. I can give it a try if you want some feedback.
My opinion of the 100D is that its small size makes it good for a second camera on a shoot or putting a pancake lens on and taking it where you normally wouldn't take a dslr. Its touchscreen controls make it a giant PITA for me since I use manual mode and do a lot of sports and action shots.