I just tested it on my miggy and it works. Picture is really okay. Sound goes through too (but it's LOUD so be cafeful).
I used a RCA=>SCART small adapted I didn't even remember I had and connected the 3 RCA to the amiga. Adapter comes with USB power cord.
Worth buying if you ask me. I've seen worse. Worth mentionning that it works on TVs but also on computer monitors. No need to buy an expensive TV, no need to find rare 50Hz Acer or NEC capable monitors. Just the fact that it needs extra power supply is slightly annoying.
@fluffkitten the RGB not working is probably the reason why it doesn't work on my Oric. The Oric has RGB output (DIN => SCART), Amiga has composite (yellow RCA). On my Oric I just see very faint images, but mostly all black. Mystery solved
(too bad as I had bought that for my Oric, having already 2 monitors able to display the miggy+scandoubler/CD32 riser VGA outputs, now I know that my third monitor can do it too)