I just picked up the IK Multimedia iRig Pro this week, after selling my (perfectly capable) Apogee Jam.
This device covers a lot of ground in a device not much bigger than two packs of Bubblicious, and even has room for a battery for the phantom power (more on that later).
The iRig Pro allows for three connections: direct guitar via 1/4", microphone via XLR (with phantom power, if needed), and MIDI via weird 1/8" to 5-pin MIDI cable (included).
This in turn connects to the iPhone or iPad via Lightning or 30-pin, both of which are included as well.
Thus far, I've ran a couple electrics of varying pickup strength through it, as well as a large diaphragm condenser mic, and all work very well. There's very little, if any noise to be detected, and, as long as you kill all other open apps, very little latency. The mic pre is powered by a single 9v battery, and it sounds impressive for a device of this size and cost. In fact, I don't think my Steinberg interface is any better. It's extremely easy getting proper levels for it, just by following the LED indicators, and watching the virtual VU meter in GB.
Because there's still no headphone out of the device itself, you'll need to utilize the iOS device's regular headphone out for connectivity. I don't really view that as too big of a setback, given that cables are readily available to adapt it to whatever you need.
MIDI works really well too, particularly with GarageBand and Sampletank's virtual instruments. In this case, I used my YRG funky guitar-shaped MIDI controller, which has the 5-pin output. The YRG performed here as it always does connected to anything else, which is to say quite nicely.
All in all, it may seem a bit odd to want to connect all of this stuff to a little phone, and in the case of the condenser mic, it probably is. But the strength of it is that I can jam on an electric with just my phone, I can do MIDI work and acoustic guitar on my iPad, and ANY of that is very simply imported into Logic X, and from there can be continued to be worked on. MIDI in particular is actually a blast to work on with the iPad, due to the touchscreen.
What I have found cool for awhile now is to work entirely in GarageBand, recording electrics with their (somewhat mediocre) amp models, instruments, etc. Then when imported into Logic, I simply swap the amp modeling for Amplitube or GuitarRig 5, the drums for EZ Drummer (since it's just MIDI), and the virtual instruments for Sampletank or a Logic instrument (since it's also MIDI). The overall flexibility is amazing, and a lot of fun.
Overall, I definitely recommend the iRig Pro. It's more flexible than the iRig HD, Jam, or L6 Sonicport, and the sound quality is far superior to the original iRig stuff.
Wirelessly posted (like MAGIC!)