Evernote for iPhone is speedier than ever and now supports offline notebooks and local note caching, includes enhanced note editing, boasts offline search, supports lengthier audio notes, and includes premium purchase options from within the app.
Perhaps the most notable change is the addition of offline notebooks. It's a premium feature designed for those Evernote users who can't live without their notes when they're not online. From the Sync tab, scroll down to select Settings -> Offline Notebooks. You'll see a list of your notebooks, allowing you to select all or individual notebooks, which will be fully downloaded to your phone for access -- regardless of whether or not you have an Internet connection.
All users can also take advantage of local note caching; now any note you create or view from your iPhone is cached locally, making it accessible in the future without a network connection.
Another upgrade that's perfect for heavy users of Evernote's audio notes (i.e. me) is the newly upped duration, so users can now record up to 20 minutes of audio on their iPhone.
Of course, an application is only as good as the user experience, and while Evernote's app has never disappointed, the new version dramatically improves the overall experience in terms of speed. You'll immediately notice that everything from syncing, searching, browsing, making new notes and launching the app feels so much faster.