Let's assume you have no legacy Windows tablets to worry about. You still have to deal with what my colleague J. Peter Bruzzese called Windows 8's Frankenstein user interface. An Intel-based tablet runs both the Metro interface, which Microsoft now calls Windows RT, and the traditional Windows 7 interface, which it calls the Desktop. The two environments interact poorly and require you to change mental gears each time you switch among them. (ARM tablets will run only Windows RT, which will include a full version of Office, Microsoft promises.)
The first thing you'll notice is that although Metro features large app tiles and big labels, much of the text in settings and apps is too small to read if you're over 25. Be sure to go to the PC Settings widget and adjust the display by enabling Make Everything on Your Screen Bigger in the Ease of Access settings. This should be the default.
Because of Windows 8's schizophrenic design on Intel devices, the "Windows 7" Desktop is unaffected by the Metro UI settings, and it's highly unreadable. Worse, menu items, ribbon bar options, and so on are very hard to accurately touch, given their small size and close proximity.
You'll need to go to the Control Panel and adjust the Ease of Access settings: Tap Optimize Visual display and then Change the Size of the Text and Icons. The resulting screen works similarly to the Appearance pane in Windows XP's Display control panel: Select Medium as the size and adjust the individual UI elements via the pop-up menu below to at least 10 points. Until you make these changes, be sure you have reading glasses on so that you can see and tap the interface elements.
Text and icon size may sound like a quibbling issue, but if you can't see what's onscreen and interact with it, you can't really use a tablet. Windows 8 should be configured out of the box to be readable and touchable -- like the iPad and Android tablets -- with universal options for larger and smaller UI display for users whose vision is highly acute or worse than average.
Like Windows Vista, options are scattered throughout the two operating systems, making system configuration a real pain. As the iPad and Android tablets show, a universal settings app is a must. Windows 8 doesn't have one.
Getting around the two Windows
Once you get Windows 8's two halves at a readable resolution, you should find the Metro portion fairly easy to use. It takes a while to acclimate to the required gestures, but they are fairly consistent.
For example, swipe from the right side to get basic system options through what is called the charms bar: Search; Share (for sending content via email, social networks, and so on); Start (which toggles between the tile-laden Metro Start screen and the Windows 7 Desktop); Devices (which lets you add peripherals); and Settings (which opens the Metro equivalent of the Windows 7 Control Panel). Swipe from the bottom edge to open up options for the current application. The Samsung Slate on which I tested Windows 8 and Office 2013 also has a physical Start button that saves you from using the gesture.
Some applications use the pinch and zoom gestures to shrink and enlarge their contents, and some opt for the swipe-from-the-top gesture to open thumbnail previews of open documents or windows. Internet Explorer 10 in Metro uses that technique, for example.