We've been examining and dissecting beta versions of Windows 8 for almost a year. In that time, a few traits have become eminently clear. First and foremost, no matter what you think about Windows 8's design, it's a towering engineering achievement: Microsoft managed to bolt a very capable, modern, touch-friendly interface (I'll stick with calling it Metro for now) onto a stalwart (some would say stodgy) workhorse, coming up with a product that's familiar to more than a billion users, and forward-looking at the same time. That's quite an accomplishment.

But sometimes engineering achievements are appreciated only by the engineers. From the user's standpoint, Windows 8 is a failure -- an awkward mishmash that pulls the user in two directions at once. Users attracted to the new touch-friendly Metro GUI will dislike the old touch-hostile desktop underneath. By the same token, users who rely on the traditional Windows desktop will dislike having to navigate Metro to find settings and apps they intuitively locate in Windows 7. Microsoft has moved the cheese.

[ See how Windows 8 stacks up against Apple's OS X Mountain Lion in our deathmatch comparison review. | Windows 8 is here! InfoWorld can help you get ready with the Windows 8 Deep Dive PDF special report, which explains Microsoft's bold new direction for Windows, the new Metro interface for tablet and desktop apps, the transition from Windows 7, and more. | Stay abreast of key Microsoft technologies in our Technology: Microsoft newsletter. ]

Now that Windows 8 has arrived (today for MSDN and TechNet subscribers, and tomorrow for Microsoft Partner Network members and Volume Licensees), the harsh analogies -- "Windows Frankenstein," "Dr. Jekyll and Mr. Hyde operating system" -- may be applied conclusively. While Windows 8 inherits many of the advantages of Windows 7 -- the manageability, the security (plus integrated antivirus), and the broad compatibility with existing hardware and software -- it takes an axe to usability. The lagging, limited, often hamstrung Metro apps don't help.

In this review of the final, RTM version of Windows 8, I'm not going to reexamine what's come before; almost everything discussed in my Release Preview review and in my Consumer Preview review still stands. There's no Start button on the desktop, and the utilities that managed to graft Start onto older beta versions don't work with the final RTM Win8. The new Metro Start screen remains relentlessly two-dimensional with flipping tiles that look like LEDs on the Vegas Strip. Moving from Metro to desktop and back again, especially on a large and touch-deprived monitor, will have you reaching for the Dramamine.

I can confirm after months in the trenches and talking with many hundreds of testers that anyone who defines "real work" as typing and mousing won't like Windows 8 one little bit. Let's take that as a given and move on from there.