10 Reasons Why the URSA Mini 4.6k is better than the Red Raven is the title of a thread posted to the bmcuser forum. Of course there is a bias towards Blackmagic at this forum but that does not necessarily make them wrong. This thread is worth a read for those debating between the URSA Mini 4.6K and the RED Raven.
We like both cameras but we wish a fully kitted-out RED cost less.
And in regards to the Ursa Mini 4K see this new article from Red Shark: The beauty of blur: Ursa Mini 4K & Canon 60mm 2.8 Macro