Though the Surface has the same Office 2013 you get on a PC, using it on a Surface is annoying. The big reason: Text selection is very difficult with the touchscreen -- in Office and other apps. You'd think you can tap on text to move the cursor position, but that doesn't work. Instead, the text is selected sometimes, and contextual menus appear other times. (It seems to depend on how long you hold the tap.)
What you need to do is use the trackpad on the Touch Keyboard cover bundled with most Surface configurations to position your cursor in text. I also found that using the cover's cursor keys rather than trying to use the trackpad was more accurate when doing fine editing, such as moving the cursor a few characters from the current location.
If you're not at a desk or using a surface such as an airline tray table that puts the screen at a hard-to-read angle (the screen angle is not adjustable), you have to go through the onscreen keyboard to edit and the touchscreen to select. My condolences -- you're in for a rough experience. The onscreen keyboard is well designed, but the default version doesn't have the cursor keys you'll realistically need if using Office. Instead, you have to switch to the full onscreen keyboard, which is not as well-suited for touch typing as the standard onscreen keyboard is.
It's ironic that Microsoft's premier touch device needs a traditional keyboard and trackpad to make Office useful. The Windows RT touch UI (the same as Windows 8's) simply doesn't work well with legacy Windows applications -- including Office 2013, despite a cleaner design than Office 2010.
The Web doesn't quite workInput issues aren't limited to text entry and editing. I wanted to write this review on the Surface itself, but I couldn't. Why? Because the Internet Explorer 10 browser -- both the limited Metro version and the full version that comes with Office 2013 -- works poorly with websites using AJAX controls. For example, I could not select text in the Drupal-based InfoWorld content management system's text fields when using IE10, as I can in Android's and iOS's browsers. The TinyMCE plug-in that provides Office-like formatting features also does not work in IE10; the controls are visible but don't respond to taps. By contrast, they work in iOS, though only partially in Android.
I also experienced problems using Google Docs on the Surface's IE10. Text selection was very difficult, even with the Touch Cover's trackpad, though its formatting controls worked.
Then there was the problem of using menus in IE10 -- I often couldn't. If a menu had more entries than fit onscreen and thus required scrolling, I was out of luck because I could not scroll through them in IE10. The scroll gesture closed the menus, as did trying to tap the scroll arrows in the menus. IE10 often couldn't handle list-based menus (using <li> tags), where you tap the first displayed option to open the menu or tap and hold briefly the displayed option to open that option's page; it was difficult in IE 10 to display the list, and when it did show up, it disappeared in a blink of an eye. Both iOS and Android browsers work just fine with all such menus.
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