I was in the XVIII Corps Automation Management Office in '83-'84 when we bought at least one of these things. They were militarized models with a different, more dust-proof, with fewer electronic emissions. Worked fine: although the GriD-OS was different, it was just as usable as PC-DOS and MS-DOS. The orange screen was different too, but quite usable. (Note the upper-case "D" in "GriD" .. the company was quite insistent on that and would have their feelings hurt if you didn't type it that way in correspondence.)
I seem to recall them costing about $5K back then, quite a bit of money, especially compared to the Apple II's we were using for other purposes. We even took one down to Grenada during the little expedition down there, where it promptly disappeared on its way back for trouble-shooting. (I'm still proud of my successful effort to track it down from Grenada to C-141 to "captured" Soviet truck cab to .. well, it ended up in the supply room of an infantry company in the 82d Airborne Division, where the first sergeant insisted he was just keeping it secure while he went on leave. Could be: he didn't take it home with him :-) I'd have called in El Cid if that had been the case, but as it was I accepted his explanation and just took the GriD back to the office.. Amazing what you can actually accomplish when you're a Special Forces sergeant major :-)
Whole idea was to "automate the Corps" and its subordinate unit headquarters. Very interesting times, and we weren't spending much money or resources at all compared to some other agencies we heard about. We actually got more practical use from the networked Apple II's than we did from the stand-alone (but NOT portable: no batteries) Grids. All history now, ancient history at that, but interesting times indeed.