Interested in high resolution recording with an iOS device? It may be worth checking out the RØDE iXY which for $199 gets you a pair of cardiod capsule microphones which attach to the docking port on your iPad or iPhone (note that you will be holding your device upside down though it hardly matters).
Using the associated app you can record at 24-bit/96Khz – good enough to allow some further processing while retaining high quality.
Suggested uses are recording concerts, broadcasting, or attaching to a camera for video with superior sound (though it might be easier to use a conventional external microphone).
Currently I travel with a separate device for recording so something like this is interesting. On the other hand, the recorder I use is small and light, the batteries last for days, and I can plug in any external microphone or use the one built-in. Still, an advantage of the RØDE iXY approach is that you get to use a lovely colour app for recording, and have one less device to keep charged up on the road.