People still think it's crazy that anyone would even consider using an iPad as a productivity device. But even in advance of iOS 9, which will arrive this fall with some major new iPad productivity features, using the iPad to get real work done isn't the computer equivalent of stuffing a dozen clowns in a Volkswaken Beetle. Real, deep, professional-level iPad apps are here today.
Then there's the file-transfer engine, which is based on Panic's venerable Transmit FTP client that started on the Mac and also now runs on iOS. Transmit's been my FTP tool of choice for several years now, and it's rock solid, with support for FTP, SFTP, WebDAV, S3, and several other transport protocols.
Then there's Editorial, a $10 app that looks like a generic text editor, but is actually much more. Editorial contains a full Python interpreter, allowing you to create insanely powerful scripted workflows to make it easy to write code, articles, or novels.
Editorial's automation tools (which include pre-written blocks, so you don't have to teach yourself Python in order to use them) and custom text snippets feature are enhanced by an extension to the software keyboard that brings snippets and frequently used special characters to the foreground.
I know numerous creative professionals who swear by Editorial for all their iOS-based writing needs. I've been writing in the same text editor for nearly 20 years, and Editorial may be the first iOS app that I'd consider on par. I could turn to writing entirely on the iPad and have confidence that the scripts and shortcuts I've built on my Mac could be rebuilt easily inside Editorial.
While the App Store is littered with cheap and free to-do list apps, OmniFocus is more than that. It's actually more of a life manager, with the power and flexibility to support anything from traditional GTD workflows to entirely idiosyncratic ones.
iPad productivity isn't for everyone--I enjoy my 27-inch Retina iMac, thank you very much--but the freedom and portability than an iPad can provide can be a compelling alternative for some, and a lifestyle for others. My colleague Federico Viticci needed a small device when he was hospitalized with cancer, and to this day leads a life so mobile--from couch to kitchen to cafe to car--that he can't imagine going back to a traditional laptop, let alone a desktop. But maybe you're just someone who's trying to get away for the weekend while still having the option to get some serious work done (or be on call in case something bad happens back at the office). The iPad can provide there, too.
So no, not everyone needs to chuck their PC and use an iPad full time. But don't go telling me it can't be a professional-level productivity tool. Because after seeing Coda 2 this week, I know for a fact that that's not true.