FWIW I keep my new JH13's in my ear most of the day. I bought the cable with the mic about 3 days after getting them (and the original cable) in order to use them for conf. calls, etc. I am on the phone much of the day and travel for work a bunch... so I think that cable will be my primary pretty much. That said, I still have the original cable and keep it in the metal case that the JH13's came in.
Net: The fit of the ear phone is really good. It's comfortable. The earphones are not too heavy. I take them out when not on calls (or leave one ear in) to provide my ears a rest, but for the most part I just leave them in b/c they block out a lot of sounds that can distract me when working at my desk at home.
Source: Sort of like you I'm starting to do my due diligence on the source. The immediate slap in the face on how clear music can be has now got me thinking- what could it be if I listened with a better source? I currently use an iPhone 4S which plays .flac files via a free player I downloaded out of iTunes. These flacs are cut down by the internal DAC... so aren't the 24-bit that they could be... The decision now: Buy an external DAC+AMP (i.e. something like the Sony PHA-2, hifi-M8, etc.) or get a dedicated DAP (AK120, etc.).
Cable: Although a complete noob (take whatever I say with a grain of salt) I *think I can* hear a difference between the cable that does not have the mic (that which came with the IEMs originally) and that which I bought a few days later from JHA. I am probably the last person who should be writing an A/B compare, but the cable without the mic sounds a little more "full" or brings a little more sound stage to the music. The cable with the mic sounds a little more thin.
- The compare I am using is a flac of Radiohead "Everything in Its Right Place" ... samples of Thom Yorke's voice -> when the bass imitates-> where the drums start -> voice
Although both present the music clearly, the original cables seem more fun. Less surgical perhaps?