I've receiver my IO Direct from Misteraddons, the Saturn version.
I have to say, the build quality on the entire thing looks really solid and the three buttons feel good to press.
No issues in connecting to the DE10 and inserting power and HDMI bridges, it all falls into place like LEGO bricks.
The Saturn cable, which I also ordered from them, also feels quality to the touch. Tested on my BVM and it works without a problem. Can't really comment on the video performance versus an HDMI-VGA dongle because I haven't made a side by side comparison but I'm sure the video is top quality.
Audio is routed via the same Saturn cable so it uses the IO Direct's DAC. Again, can't comment on the audio quality as I haven't made any direct tests. I have to buy a mini toslink cable to connect to my AV receiver which for me is a preferred option.
The USB-C for powering is awesome, no more clunky power bricks for my Mister. I don't know how many ampers the USB ports on my PC provide but I've connected to one of them (USB 3, of course) and it seems to be working just fine.
I've also ordered a Wifi/BT module from Misteraddons and it works perfectly. My Megadrive Switch Online joypad was paired in a second, lovely!
The fact that you can install a Noctua fan makes this a better option than the Retrocastle's alternative for me. There is a jumper for 3.3V-5V so you can really make your setup noiseless.
All in all, the IO Direct from Misteraddons is an awesome piece of tech which I would fully recommend.
Also, the help chat on their page is always there to answer your questions, big props for that.
From my limited testing I would give this board a 9/10. The only reason why it's not a perfect 10 is not having USB ports to make the bottom USB hub redundant.
If you're looking for an IO board, this is it