Hybrid shooter and C300 III and R5 owner who's looked at the C70 with a lot of interest but never pulled the trigger. This was an easy preorder. Canon priced it at the exactly right number to be competitive.
A few things that stand out to me:
No IBIS is a good thing for video -- it drives me crazy on the R5 because it couldn't always be disabled depending on the lens (I don't know if firmware has corrected this).
Micro HDMI is surprising, but in fairness the point of the camera is to have everything in-body in a small package. This isn't a big studio production camera... it's run and gun fun. The C70 is still the better option at this price point if you're someone who wants to rig up with external monitors, V-mount batteries, etc.
XFAVC, higher bitrates, the two different menu systems, C-series features such as false color, and obviously the unlimited record time really make this a compelling camera for a hybrid shooter. You don't need anything else except ND and a lot of batteries.
If you ONLY do video, the C70 is still the obvious option in my opinion.