I currently own the X100 Pro and I agree somewhat with that assessment, however its getting better. Nowadays they at least issue monthly updates and some bugs get crushed. Besides, the Chinese version with Origin OS is supposedly a much better OS and ppl like it a lot. The Ultra will most likely be China only anyway so Origin OS.
As a former vivo smartphone user, all I can say is that vivo smartphones take outstanding shots (maybe better than any other smartphones).
However, vivo's custom UI (Funtouch OS) is an utter bulshit. It is full of bugs. Sometimes lags and freezes. Compared to Xiaomi's MIUI, it lacks a lot of features and functionalities. MIUI (or HyperOS) is a lot smoother and well polished when it comes to system elements.
I'm not even talking about vivo's absurd edge (curve) design. This design is so old that all other manufacturers have found it uncomfortable and abandoned already. But for some reason, vivo still makes phones with curved sides (displays) that makes phone very slippery at hands.
So, I only recommend vivo's phone just for photography not anything else.
In 2024, the chapter on zoom cameras in smartphones is likely to be rewritten without Samsung, one of the early co-founders of long-range zoom cameras in smartphones alongside Huawei. Ironically, the Vivo X100 Ultra contains Samsung technology, with which Vivo achieves excellent results, as new photos from its 200 MP telephoto camera demonstrate.