Back to 3.5mm?
I have an iRig HD which is basically a tiny USB interface with adapter cables so it plugs into the iPHone/iPad using the 30pin/Lightning socket. I thought this was a marked difference in quality over the cheaper iRig which used the 3.5mm... I assume it sent the signal digitally rather than line-in?
So why now go back to 3.5mm?
On my iPad, it's pretty good BTW. I'd find it fiddly on something as small as a phone.