The one thing that bothered me about the Mobile In when compared to the Apogee Jam was the way that it hangs off the bottom of my iPad. It seemed, especially with the guitar cable attached, that it was putting a lot of strain on the 30-pin connector.
My solution was to buy a 30-pin extender cable on eBay for 8 bucks, shipping included (from a U.S. address, so it only took a couple of days to get it). Works like a charm. I can plug the extender cable and tuck it under the iPad to provide strain relief, then plug the Mobil In into the cable.
The one thing to look out for is that there are apparently two different kinds of extension cables being produced by our good friends in China. Look for one where the listing explicitly states that it "is not simply for data syncing and power charging, but also supports audio, video playback and controls of your iPod or iPhone". The one I bought said exactly that, and it works like a charm. It did say that it "does not support S-video output or input for recording audio", but they must not have been referring to the digital audio path that the Mobile In utilizes, because it functions perfectly.