The C80 has internal ND and there's almost no way this one does, based on the size. C80 also has XLR, SDI, and about a bazillion buttons that this one doesn't.
On paper, the R5C had a number of advantages over the C70, including better AF and 8K shooting. But it also lacked internal ND, XLR, etc.
If I were Canon, I'd honestly be a lot more concerned about sales of the R5 II than the C80/C400 if this camera has most of the rumored specs. Especially if it has a DGO sensor, I'd gladly take that over 8K recording and 10-15 more megapixels for still photos.