1. China ROM or any china Phone doesnt support e-sim , if u need e-sim , u have to go with x200 or pro for Global version.
2. For CN ROM except Huawei , all have build in GMS (Google Mobile Services) , so u can install Google Play store and use any android app.
3. No Voice assistant like "Hello google" , u have to manually press the app to use the Google voice Assistant. So no google smart home. But all google application can be use like normal.
Other than that , it just work like a normal phone and it support 5G without problem , if u ask me is it suitable for your First time and used as main phone ? I would say NO , because using a CN ROM phone for the first time is like driving a MANUAL CAR , u have to do the setting manually , so it request some knowledge to do some setting on the phone.  But those mostly is one time setting la , once u setup the thing like "Open by default" , "Autostart permissions" , then good to go.

I share my experience , i starting with a little cheaper CN ROM phone to trying out (the Iqoo line) , because even if it's not suit me , i stil not losing too much , but since i'm more like to take challenge person , so i do figure out on youtube / reddit on how to really make the CN ROM work like a normal Global unit , and surprisingly it doesnt really bring me big problem on setting it up. After use for 2 year++ for the first time , it make me more confident with the CN ROM , starting to get 2nd phone and now 3rd phone to be my main phone without problem (this my 4-5th year of using CN ROM).

I even pass my previous IqooNeo9 CN ROM phone to my Dad , and he ask me "Why this phone so smooth and the camera so clear , screen so bright" , yes because i told him that phone was using Snapdragon 8Gen2 + 144hz refresh rate    compared to he previous realme RM699 phone , sure have a big gap , and my dad been using more than 5 month now , no any single complain from him    everything just work fine.
I'm using since OriginOS 3 , and now OriginOS 5 , i would say the delay notification is improve alot over the time , i actually facing some delay notification on OriginOS 3 quite serious , OriginOS 4 is OkOk but OriginOS 5 surprise me that.....it really work so well on notification.

U might share what is the main app or main feature u using now , so that we can try for you to see is it working well on CN ROM.

Hope that information can help u out.

Yes , if u are in China , can fully utilized the feature on phone , but it actually not bad on here because i just close the open by default browser and set to my Chrome , the AI "Xiao V" actually quite good , but it request china cloud server which will respond slow sometime , but not a big deal because i using chatgpt and gemini all the time now 

and i not so understand about responsive? I just feel even my Iqoo Neo 9 with snapdragon 8Gen2 is snappy than my samsung , and my current vivo x200s using 9400+ mediatek was as smooth as my iphone 16pm. iphone16pm sometime lock at 80-90hz actually , my vivo i set lock on 120hz all the time for all app. So i dont have responsive problem on the phone.