With respect to charging speed:
> I wonder how important it really is.
First, let me clarify: I love having a fast charging speed! If I do DCFC every single day, I am sure I would enjoy fast charging.
In reality, I do most of my charging at home. In my AZ home, I have a lot of solar energy. As such, it is free. At my CA home, I have solar panels with battery backup and charge at night with the PGE off-peak charging rate (~$0.33/kWh). It is adequate for my weekly usage.
So, the only time I use DCFC is when I do my 780-mile journey from CA to AZ. In the Lucid, I can do this trip comfortably with two en route DCFC stops. In my R1S, I usually do 3 DCFC stops. And I prefer the Rivian Adventure chargers (renewable energy), which are rated at 300kW, and usually deliver 250kW for the first 10-15min. In contrast, the EA 350kW chargers often deliver no more than 220kW, and only for about 7-10min on my 2022 AGT. Thereafter, it quickly tails off to 150kW/<100kW. Have not tried the new Ionic chargers. Wonder how much difference they make on 800+kW charging architecture.
800+kW charging en route on my roadtrips is a plus, but might not save me that much time over the years.
So, since I love to have 800V charging, my personal usage model really won't benefit too much from it. Obviously, if all things are equal, I will take 800V+V, but it is not a mjaor buying decision for my usage model.