Not all iOS text editors are created equal, but this maddeningly comprehensive chart comparing just about every feature of more than 30 of the top apps will help you find the right one for you. Compiled by Brett Terpstra, the chart is so huge that it won't fit on a 15-inch laptop screen.
Features compared include syncing support (Dropbox? iTunes?), export formats (HTML, PDF, etc), as well as useful options like word count, in-document text search and built-in web browsers.