Your points are valid. Not to really defend the pricing since $400 is a lot to ask, but most equipment in this hobby has a lot of diminishing return. Like a $1k IEM is not 3-4x times better than a $300 IEM or whatever, but the kilobuck IEM is probably better which is what justifies the price. The Go Pod is better sounding than the UTWS5 which is what really justifies the price. For me, I can't fit my custom IEMs in the UTWS5 because the 2-pin version doesn't support recessed 2-pin and my IEMs won't fit with a MMCX + 2pin adapter. So my only option is the Go Pod and despite its unnecessarily big case, it still barely fits. Maybe FiiO will add recessed 2-pin with the UTWS15 or maybe a slightly bigger case with the UTWS7 if that happens.
Generally speaking, connection and controls are pretty good in my experience with the Go Pod (I get little small issues here and there). In terms of sound, when I use my IEM + Go Pods, I don't really have a urge to use my IEM + wire + DAP because it sounds good enough and I can dance without the added weight which is a big positive for me. I do have issues with my Go Pod case and I think the UTWS5 case is better built. My hinge squeaks and is actually kind of loose since I can turn the top a little bit. The case design doesn't look that great imo and is awkward to pick up due to the angled front.