I will be shipping my kit to @Vansen tomorrow. Thank you again to everyone involved in the tour! The U18t are very familiar and balanced sounding iem in comparison to the Fourtes, yet very full in quantity and big sounding, especially in the mids and lows. It took me a while to get used to the big sound when I first got my A18s. At first, I thought the bass was too much, but it turns out everything was just big across the board. Because of their neutral sound, they are very receptive to what custom cables are designed to accomplish, delivering good to excellent synergy with most custom cables. The difference between the U and A18t was minimal but interesting. The overall sq was similar, as expected, but the A18s were about 2-3 db louder, not just with the foam tips but also with silicone tips. Not a big deal. When critically listening at similar volumes, not just the bass of the A18s, but the mids and also the highs to a lesser extent, sounded more palpable and had slightly more added texture because so much more of the customs surface area is in contact with the ears conveying the tactile sense of the sound. The difference is not nearly as huge like how you can feel the sound coming out of floor speakers with your entire body vs. just your ears when listening to headphones. It is subtle but there. Again, these are probably two of the best iems and ciems out there right now. You cannot go wrong picking either one. Lastly, I just want to mention briefly my experience ordering from 64 Audio was absolutely phenomenal. They completely left me speechless with so many things that define professionalism. Even the way they communicate with customers, small things like choice of words and mannerism are absolutely first class. I wonder why other companies are not this way, because... honestly, this is the best thing you can do for your company.