I've had my JH13 for about a week now, and I just sent them back for a refit.
After much practice, I was able to insert and remove the right earpiece without much difficulty, but it's clearly not as easy as in the Ultimate Ears instructional video. That UE dude doesn't have my ears. When the right earpiece is in, it's comfortable.
The left earpiece, however, just was not working for me. No matter what I tried, it was annoying to insert and very difficult to remove. In fact, I couldn't remove it more than a few times before my antitragus was bleeding from what I had to do to my ear to get it out. When it was in, it caused pain in various places, particularly the tragus area. (I'm looking at an anatomy diagram as I write this.) I kept hoping my ear would get used to it, but after a week it was clear that it was not getting any better.
I spoke with Jerry on the phone today about this, and he was very helpful. I explained the issues I was experiencing, and he asked a number of questions to more precisely diagnose the problem. He retrieved my earmolds and called me back. Apparently, I am in the small minority of the population with ears whose helix and canal move toward each other rather than apart, so insertion is going to be more problematic. Jerry seemed to understand the issues I was experiencing and said that buffing it down in the right places should address the issue with the left earpiece. (Although the right earpiece is inconvenient to insert and remove, it is not painful.)
So I sent them in today. I look forward to a solution, because in their original state they would just gather dust in a drawer.
The sonics are excellent. If Jerry can make the left earpiece equal to the right, I will be one very happy ephemere.
I like everything else about them. I like the color, the cable (black), and the very durable case.