I've been watching this thread for a while. I ordered 2 CSX5's - one for me, one for my wife - along with some custom colors, etc.
We've had them for about 6 weeks now and both sets are going back with professional impressions to have them remade. My set fits "ok", but doesn't completely seal in either of my ear canals. This left me with no low end bass on the IEM's, unless I pressed on them with my forefingers. I too fly a lot for work and was looking forward to the noise isolation I was expecting, but it just wasn't really there, again unless I pressed on them with my fingers. While my right ear was relatively comfortable to wear for a few hours at a time, my left ear had some discomfort in a few areas after about an hour or two of wearing.
I filled out the refit form on the website and UE sent me some comply strips. I put them on before my last trip, down near the end of the IEM. The low end was definitely improved as well as the noise isolation. The comply strips are a bit rough feeling in your ear canal, but they are not intended as a permanent solution.
My wife, on the other hand, did not have a good fit in either ear. She has really small ear canals as well as the bowl and upper area, and she could not get them to fit at all. She could only wear them for 15-20 minutes before she had considerable discomfort and her ears got hot and red.
We filled out the refit form for her as well, and sent in new pictures.
I asked about getting impressions done for her 1st, and me as a backup -- and Lorden from customer service got us both approved for new builds from custom impressions. I will say that, yes we spent about $1,600 for 2 sets with 2 leather cases and want them to be as close to perfect as possible, but overall the customer service we've received has been GREAT. Lorden has worked with me, through all my back and forth emails and photos and has provided spectacular customer service. For UE, they're getting back 2 brand new sets of IEM's that - who knows what they do with them, but through the whole process, that has gone beyond the return timeframe, they've been spectacular to work with.
In conversation with Lorden, she made it known that they will work with customers out of the return window - provided that you work with UE and provide regular updates to the fit and performance when you get them.
I'm sending our impressions in today and hope to get them back in a couple of weeks. While I have a lot of travel the next few weeks, the Mrs and I are flying to Phoenix AZ for the NASCAR race in November. I'd love to have them back by then so we can use them on the flight and at the track.