ArcaOS fully installed and functional.
The download was on Tuesday. Today (Friday) it is now my primary computer. Went quite smoothly, just a few hitches, but I'm very experienced with installing OS/2.
The user interface looks a lot more like Linux than the old OS/2 desktop did, but the underlying stuff is completely compatible. All my OS/2 software runs perfectly, except faster, and my Firefox now has video and sound.
The one thing I don't expect to run is the ancient Faxworks for desktop fax. It had to be installed before FixPack 15, because the install method used no longer existed after 15. Not a problem, I don't use desktop fax any more.
One thing they need to fix is with USB. Some KVM switches abandon the keyboard and mouse interfaces and expect them to be found on switching back, which doesn't happen. This I missed during configuration on the workbench, but it's not needed now that this is my main computer.
My old computer, RHINO, is still on the network for reference in final configuration of SERPENT1. In a few weeks it'll get a new 1 T hard disk and be updated to ArcaOS v5.0 and renamed RHINO2.
One thing that hasn't worked since Firefox 2 is printing from Firefox. The OS/2 port guys were never able to make that work - so I've always kept v18.104.22.168 on my OS/2 machine because I do a lot of printing from the browser related to developing my clovegarden.com
Web site. ArcaOS includes the CUPS printing system, but there are still some glitches to work out.
Basically, I'm quite pleased with ArcaOS.