I have this model:
https://xtrons.com/bmw-x5-e53-androi...-rom-ib9953bpl

I vastly prefer its capabilities to stock. Offline maps are super easy with Google, you just select an area and download it. It expires after a period of time, because construction happens so often, but updating the downloaded maps is easy as well. I'm not fond of connecting the unit to my phone for internet, but there are models with built in 4G as well, which I am considering an upgrade to.

Things that might make you want to keep your old stock system would be television usage (which you can also make happen with these Android units), enjoying the nostalgia of the 8 color navigation from the early 2000s, radio usage (something I don't do at all since I'm in Kuwait and don't understand Arabic. You can integrate your antenna system and such with the Android systems, I just never bothered.), or some other oddity like owning an old ass Nokia keypad phone that fits in the center console.

I see no value in keeping a car stock that has no value in it to others, but some do. I love this Android system and the rest of the audio I replaced the BMW antiquities with.