I think that one thing ACA500Plus really lacks is a decent case. It's a super versatile accelerator but when you just pull it out of the box and connect it to your Amiga, it just looks quite ugly, and I think it may really put some people off. Also most cases available online are just crappy, at best, and look out of place.
But it doesn't have to be like this, does it? Recently, I finally got around getting a 3D-printed case for my ACA500Plus. It's this one from Thingiverse: https://www.thingiverse.com/make:683677. It looks really nice, even though it's not perfect and it's 3D-printed. Check out the attached photos. It also did require some tweaks - there are no spacers to mount the card, no mount holes for additional A1200 card, one of the supports for the top of the case would block the A1200 card, so I had to cut it off, there's no mount point for an RJ45 socket (for X-Surf 500), there's no way to reach the ACA500Plus button, and so on. But if all these issues with the design were addressed, and if it was properly made via injection moulding, I think it would be a hit. As a bonus there could also be an ability to mount LEDs in the case and connect them to the accelerator, but I'm aware that this would require serious messing with the accelerator, so maybe it would be asking too much.
Nevertheless, I'd buy one for sure, even though I have mine. What do you guys think?