I was going to write up a review on Elements [iTunes link] this afternoon, but then I saw that MacWorld just posted one. They covered most of the things I was going to cover. One area they missed is a huge one: keyboard support. I bought an Apple Bluetooth keyboard to use with my iPad after I sold my MacBook, and I set out to purchase a real productivity app with which to perform actual work on the iPad. I researched Docs to Go and the other major productivity suites (most of which sync with Office, Google Docs, or both), but I bought none of them because they don't support arrow keys on external keyboards (a good point in favor of researching before you buy, because these apps are roughly $15 each). I'll say that again because it seems vaguely frakking important: they don't support arrow keys on external keyboards! What? I'm not a mouse fan and am all over my keyboard like white on rice. Hitting an arrow key and not having my word processor respond is so unacceptable that I'm not sure why they even released the software.
iWork wasn't even on my research list because I've heard too many stories of issues dinking around with the syncing, and I'm so not interested in things I have to really mess around with to make work.
Anyway, just when I was about to seriously regret offloading my laptop, I found Elements, and I've been really happy with it. I'm a longtime Dropbox user, so the seamless sync appealed to me (and it IS seamless). It supports external keyboards fully, including not only basic arrowing but also shortcuts for skipping from word to word and paragraph to paragraph, thus allowing me to speed around a document on my iPad at the same lightning speed as on my iMac. It supports TextExpander. And it's only $5.
Why so cheap? Probably because it's all about plain text. Folks who need to toss documents back and forth between the iPad and desktop and retain formatting are not going to find Elements useful. It's not a Word replacement. It makes an Elements folder in your Dropbox folder and populates it with plain text files. It does not sync with any other suite. I'm unperturbed by this because most of the stuff I write is destined for the Web anyway, so if I feel compelled to format something I just toss in some HTML. If I've just got my iPad and need to create a Word-ish document, I hammer it out in plain text and then just copy it into Google Docs or, if I have time to let it start up, Word. But I would find this unworkable if I had to do it very often.
Bottom line: Elements is an excellent solution for Dropbox users who want a lean, mean, painlessly syncing text editor for their iPads (technically it works on the iPhone as well, but I find working with text on the iPhone so painful that I haven't tried it) and who need their dang keyboard shortcuts.
Update 9/29/10: Now there's PlainText [review link], which seems to do the same thing as Elements but is free. Don't know about the keyboard support.