If free is more your pace, then consider Documents by Readdle, a surprising versatile app for consumers and businesses alike.
As the name suggests, Documents by Readdle is first and foremost a document viewer, therefore it can display any number of document types, including .doc and .docx files (Microsoft Word), .ppt (PowerPoint), .xls (Excel), .txt, .pdf, and others. Within a document you can search, bookmark, adjust brightness and email the file.
I've no idea why I do so much writing on my iPad. Convenience -- being able to write anywhere -- is part of it, comfort is another part.
I like being able to write while joining in family fun. (Yes, I write all the time, everywhere. Everyone's used to it by now.)
Most of my drafts are done in Drafts (snicker), on the iPad and I revise longer projects, which start out on my Mac in Scrivener, in iAnnotate.
Documents is completely new to me. Since my iPad workflow is so well established, I may not use it, but I'll definitely download it to see what it's like.
If I do make it part of my workflow, I'll let you know... ;-)