I don't think either can compare to an actual dedicated video recorder. Sure, a dslr would work for most amateur recordings. But, for any special event, I think you need a video recorder for the best quality.
As a major in videography, cellphones will not in the foreseeable future be able to compete toe to toe with a mid to high end dslr. With that being said phones like the pixel and s7 are still very good for being a prime lens on the back of a phone.