I'm a little surprised no one noticed the ACA500 here before. It's been talked about for months and months on EAB and other sites. Especially since it's another ACA-card by Jens it shouldn't be such a suprise.
Apart from that, I am also of the opinion this card is severely flawed but I almost got my head bitten of by Jens when I mentioned this on EAB. :-/
What I like about it is the aim at low cost, the CF-connectors and the only slightly faster cpu (I don't need it to be a power house, I have other miggies for that).
The original design was meant to have a 68020 @ 14 MHz, 4 MB ram (if I am not mistaken) and would be internal, which would be much more to my liking.
Now it turns out to be a 14 MHz 68000 (not a problem for me) with 2 MB ram (which ís a problem for me) and it will be external (which is simply not acceptable for me).
Kipper2k seems to be working on a much more interesting solution, combining his 4/8 MB fast ram expansion with the IDE68K in one internal device. Also expected to be a low cost solution, but without several of the severe design flawes (in my opinion) the ACA500 has.
Mind you, for the most part I really like the products Jens makes and sells and I understand he wants to make a profit, but I can't imagine this being a succesfull design. He aims it at the returning A500 user without the ability to add an internal card. I really doubt there is a market for that. Returning A500 users without that knowledge will, I expect, not even think about adding anything to an A500, as they don't even have any idea about the existence of any such products. So, the product will mostly be sold to existing users, most of them being able to add an internal card to the A500 by themselves.
The Indivision ECS for example is a fantastic product, as are the ACA630, the A604 (this combo makes the A600 a fantastic computer!), the Indivision AGA mk I (which I all have) and the ACA1220/123x also seem to be great, but the ACA500 goes from barely acceptable (when it was to be the ACA520) to, well, almost embarrassing.