I haven't done any actual comparisons but from the footage I've shot with both so far the 5D has less noise in low light but in nicely lit scenes they are pretty similar.. I'll be posting a mini-documentary next week that was shot with both the XF100 and 5D so stay tuned. Which do I prefer.... both. The XLR inputs, auto focus, articulating screen, peaking and zebra functions are just a handful of features of the XF100 that the 5D doesn't have. The 5D's picture quality, interchangeable lenses, and portability are a few reasons why I continue to use it. For what I shoot - I need them both and like them equally. Always good to have multiple tools at hand. The XF100 is my first camcorder but being able to have my NTG-3 shotgun mic and wireless LAV recording into the camera at the same time via the XLR inputs to two separate channels makes things A LOT easier in post by not have to sync the audio or pay extra $ for Plural Eyes. The DOF of the 5D w/ good glass is priceless for those creative shots! I definitely don't plan on getting rid of neither anytime soon.