You can create rich, stunning documents on the iPad with Pages -- not with all the bells and whistles available on a Mac or PC in Microsoft Word, but much more than in any other mobile word processor. It's also easy to use. But Pages has two major flaws that could kill it as an option for many companies and a third flaw you should know of in order to avoid it.
The first flaw is that it doesn't retain style sheets in the documents it saves. That's significant damage to the original file and will cause major issues if the document goes through any publishing workflow, such as for eventual HTML conversion or use in Adobe InDesign. The styles' text formatting is retained, but as local formatting only. Pages does have a styles capability that applies predefined formatting to text, but it does not apply a style sheet that is editable by Pages or Word; the Pages "styles" are just local formatting groups.
The second flaw is not so fatal: It doesn't work with cloud storage services such as Google Docs, Dropbox, and Box.net. If you want to share files with others, your options are limited to email, syncing to your computer via iTunes and sharing from there, or Apple's MobileMe service.
The third flaw is a design foible: Any changes you make to a document are saved immediately in the original. You can't save the changed file later and retain the original file as is. The work-around is to make a duplicate of the file within Pages before you open it.
Quickoffice. Quickoffice's word processor is simple, with straightforward controls for basic formatting, such as font, text size, paragraph alignment, and lists. There are no layout controls, so you can use Quickoffice only to work on text. But Quickoffice retains the style sheets in your imported documents, so they're intact when you later export a document, even though it doesn't let you create, edit, or apply styles.
Quickoffice can connect to Box.net, Dropbox, Google Docs, and MobileMe cloud storage, as well as to a computer directly over Wi-Fi. It also of course can email documents, and it provides a Save As option, as well as an internal folder structure so that you can organize your documents.
But Quickoffice has no search-and-replace or even search-only capability, nor a word counter.
DocsToGo. DataViz's app is similar to Quickoffice in terms of its capabilities -- they're simple text editors with basic formatting options. However, DocsToGo does offer search and replace, as well as word counting. But I can't recommend DocsToGo due to a really dumb UI design: All the controls are at the bottom of the screen, where they become hidden by the on-screen keyboard. This means hiding the keyboard to do any formatting each and every time -- a real productivity killer. (Pages and Quickoffice put the controls at the top of the screen.)