Apple A/UX always felt unfinished to me. Great leveraging the partnership with IBM, but IIRC some Mac apps would fail to run in some weird ways.

I played with it as a sysadmin at work, on a Mac IIfx with thousands of dollars of RAM installed.

Did you ever get to play with the Apple Network Server? A rebadged IBM/6000 box.

Apple's approach to distributed network services was really great...

Alas. This era was like the Xerox Alto -- visionary, but required $10,000 to run.

I had it on an SE/30: 16 MHz 68030, maxed out at 8MB of RAM, 1M per stick. (Later you could get bigger sticks; I never did.) It had floating point hardware 5x as fast as the IBM PC-AT's coprocessor. The whole machine with 80M disk was $2400, in 1990 dollars. It had one slot, taken by the 10Mb/s ethernet card, and a 512x342 monochrome 1-bit-deep display.

It ran MacOS7's GUI, and it was as responsive as anything you run today.

Huh, I’ve never heard of it before now. Unix based but with system 7’s UI sounds very appealing.