Same. Switching Siri language to English (US) enables Apple Intelligence after a lengthy download without progress indicator. At least on my 16 Pro. On my iPad Pro M2 it states it's downloading for hours on end now with no network activity - even after dis-/enabling the feature and restarting the device. Still takes up the same 6.13 GB of storage space though.
I know it's the first beta of 18.4, but to me iOS 18 in general feels very unpolished.
Works for me in Germany with my iPhone 16 pro set to Germany and German language.
So far tested the writing tools (in German), Image Playground, Visual intelligence and "Bereinigen" in Photos. I activated message prios, not sure if it works though...
Siri animation is nice, but I think Siri is not more "intelligent" than before! ;-) But I think this will come with 18.5.
Battery life seems to be also quite good.
Not sure why some people have problems with German language. You sure everything AI related is downloaded already?