I noticed you mentioned “feel” and I see someone addressed this, but I can second the fact that the playing experience is different. When I was shopping for my Stingray, I tried a lot, and noticed the Sterlings felt more like jazz basses due to the narrower nut. The US stingray feels very similar to an older P-bass with the wide nut.
The US stingray necks also felt more refined than the sterlings. It’s one of those indescribable things you have to feel to understand. It just feels like way more… care or attention.. is put into the US necks.
The bodies are pretty much interchangeable, though you can tell the US models have a vastly superior finish application.
Electronics are much more robust on the US models as well (yes, I removed the Pickguard and control plates on a couple when checking them out with the shop owner’s permission of course).
The neck finish is hard to describe too, but I’ll say while the sterling necks are comfortable and finished well in my experience, the US models were absolutely perfect feeling. Smooth and soft like a slight dusting of baby powder is on them. The neck profiles were also slightly inconsistent with the sterlings (just enough to feel a difference). Every single US model I tried felt exactly, EXACTLY, the same which speaks to the precision and consistency with EBMM US manufacturing.
Do I think the US model (I paid $2599 for mine) is worth that much more than the Sterlings (the models I tried were in the $749-$899 range)? For me, yes absolutely. I would say you should invest the time in finding examples of both and physically interacting with them to come to a conclusion on whether or not the difference in feel is worth the difference in price.
Sound wise, I think that’s simply going to be a personal preference thing. I’m sure this won’t help much, but while they both sound very good, the US models sound more “grown up” and “well-rounded” and “open” for lack of better terms. The Sterlings sounded more “tight” and “scooped” and “less mature” if that even makes sense.