I feel like I should share my experience dealing with JH Audio, it's been very pleasant. They answered my questions quickly and politely via both email and telephone. This was before and after I made my purchase. Maybe it would be different for someone quizzing them on the phone about a used pair they haven't even bought yet.
The Layla's are a very well built, great sounding iem, one of the best available at this time in my opinion. . The fact that they won't honor a warranty for a second owner is pretty common and totally understandable. I'm confident that if I were to need anything as far as service or cleaning it will be handled quickly and professionally. If work is needed after the warranty is up, that would be on my dime. Again, totally understandable...I did not see ANY pre owned "lightly used" pairs available anywhere, let alone at "good deals". I think that most people that buy these, keep them. I like the idea of "new" from an authorized dealer with a valid warranty anyway, especially at these prices.
As far as the fit, they fit me great. I can barely tell they are there. You'd just have to try them on for yourselves. If you are on the fence about them, you will not be disappointed with the excellent sound they produce, they really are awesome. I have mine paired with an Ak300 and I'm pretty much done looking at anything else these days. It would be hard to convince me that something is better, it may be a different sound, not necessarily better. Eric