I am replying to my own question here, as a re-reply to the first reply so it will appear near the top. I installed Win 8, despite my misgivings, almost immediately after sending the email above, and my impression is nearly wholly positive so far. Indeed, the only thing wrong is that they removed that option to boot directly to the desktop-optimized "classic" interface, but they did make the absence of this feature nearly irrelevant. The following is my first-impressions review:
I installed 64-bit Win 8 Pro over Win 7 Pro on my main desktop computer, a Core i7 2600K with 16 GB RAM and an OCZ Vertex 3 MaxIOPS SSD as the system/application drive. I installed it from distribution disk and have been using it now since the first day of its public production release.
The installation was far simpler than I imagined it would be, or even could be. It was no more difficult than the installation of any application from disk, and was done from the Windows 7 desktop -- no need to boot to the disk at all unless you want to take advantage of more custom installation options. It took less than 15 minutes, no more time, and far less complex, than installation of MS Office or Adobe CS.
The only complication during installation was that it gave me a message saying my Network Interface Card driver was incompatible and needed to be removed, and it allowed me to hit a button and remove it from there. It then proceeded with the installation, and transparently installed a compatible driver from its own distribution.
The Metro interface is a bit of a shocker and does indeed involve some learning curve, but it's not steep by any stretch of the imagination, at least not in my opinion. After a few minutes you get the hang of configuring it to your liking, as much as it can be, in any event, and it is very intelligently and logically designed, which flattens out the learning curve significantly. But it's nearly irrelevant in any event, as my already-installed applications open in the same old desktop I grew so comfortable with (since the days of Win 95, which was less of a change from Windows 3 than this is from Windows 7). Furthermore, the old, comfy desktop remains after closing the app and functions very nearly identically to the way it worked with Windows 7. Nevertheless, Metro is a visually attractive interface to greet you on bootup, and that's about the only time I see it. And multitasking is only inconvenient in Metro -- it works just like it did before from the desktop.
The ribbon interface for folders takes a bit of getting used to just like it did when introduced in Office, but after you grow accustomed to it, it really is an improvement.
The biggest problem with Metro is that it opens everything full-screen without even the option to window it. I very seldom open any applications other than video players full-screen, and my preference for windowed apps is one of the reasons I have a 29" monitor. I have absolutely no desire to go to a touchscreen -- I like keeping my monitor as free as possible from fingerprints.
Nearly everything worked from the git-go, even third-party apps and utilities, some of which are very old, that I've found over the years on places like MajorGeeks (some even dating back to Stroud's Consummate Winsock Apps!). The only exceptions I have discovered so far have been my Aero-based skin for the music player app WinAmp (the app works fine, but only with the "Classic" skin), and, more seriously, my HP AIO printer drivers -- it prints fine but could not access the scanner or fax. HP had no full-featured Win 8 drivers on line, but put them up on October 31 (odd since Win 8 has been around in beta for so very long -- curse you, Carly Fiorina, for what you did to that formerly great company HP).
Bootup from cold is startlingly fast, WAY faster than Win 7, and you could probably shutdown and reboot ten times in the time it took to boot Vista from cold. Apps all feel crisper. So far it has been 100% stable and rock solid.
The absence -- indeed the removal -- of the old Minesweeper, Spider Solitaire and Freecell is really rude and made me angry. Why on earth did Microsoft do that? They offer them for free from their "Store," but they only play full-screen, and on the net, from the Metro interface, and starting them up is far more cumbersome even from there. BAD Microsoft! Hopefully SP1 will correct this silly offense. Why on earth would anybody want to play solitaire against others, or Minesweeper in full screen mode?
It did take me a moment to discover how to shut down the computer without the "Start" button. You have to go all the way back to Win 95 for this -- you just use the power button on the CPU, but unlike 95 you have no need to shut down Windows first. You can shut down from the screen as well, although it's not obvious how (part of that learning curve). This is logical and represents, in my opinion, an improvement. But then, I have my desktop computer on my actual desktop; people who don't may find the CPU switch to be an inconvenient reach, although this is obviously not an issue with laptops.
For me, however, the bottom line is that, on my computer under Windows 8, EVERYTHING is faster. Decoding very large compressed files is almost instantaneous. Manipulation of huge databases is noticeably faster. It leaves more RAM free for application use. Every keystroke feels crispier. And the stability is remarkable -- even my flakiest apps have run under severe load without a hitch. It's going on all my computers because, IMO, it really IS an improvement, even over that Vista service pack they called Windows 7.