I actually have one of the Opalvision Video Editing sets. Unfortunately it causes the Amiga not to boot. Dont know what part is causing the problem and someday will try transferring the Roaster chip and the rest piece by piece to a known working Opalvision card I have since, I suspect, it more likely a bad Opalvision card would cause the Amiga to fail on self test instead of the rest of it.
I never had a Digi-View but was always impressed by what they could do back then. I ended up getting a Mimietics Framebuffer since it could display as well as grab in full NTSC images output from VistaPro, Imagine, and even with ArtPro you could send anything to it. As for Digi-Paint, I always hated HAM paint programs. Used Deluxe Paint mostly. Tried otu Photon paint, then moved to Brilliance. The Framebuffer had a paint program designed for it, uPaint I think it was, that allowed you to paint the NTSC images to the Framebuffer by using the trick of it being in black and white on the native Amiga screen until send back to the Framebuffer.
Much later I got Opalvision, much easier obviously with its paint program and drawing direct to the display. Then a DMI Resolver board that has a paint program that actually runs on the board and was very fast, not tied into the Amiga for its speed. later in my quest for Amiga goodness I got the external "boxes" that enhanced the Amiga display. Ham-E which is hard to find since they came and went from the market so fast, DCTV and Graffiti.