On my phone? No its not big enough. On My Kindle Fire? Yes. Have a WiP wrote entirely on a Kindle Fire using Quick Office Pro, its about 40 percent done. I never timed it but i would be willing to bet my word count per minute is about the same or better as a traditional keyboard, and its way more portable and pleasing to use then a laptop or netbook. It does have its limitations, mainly with editing (cut copy paste etc), so i would say it is limited to doing the first draft but all and all it has helped my writing process by making it more accessible.