In case you're not in a rush to replace anything, all us graphene fans are anxiously awaiting their first "sold with graphene" phones from Motorola. No ETA though.
Never used the stock rom on it, purchased it, turned it on, and immediately flashed it. BUT compared to my last "normal" android? (Smasnug- I'll never NOT call them that thanks to a certain Aussie on YT) No. Nothing. That said I'm middle aged and never even considered using stuff like contactless payments with a phone, etc. Never saw the appeal of increased risk just to look like a douchebag at the checkout aisle or the drive through. Your mileage may vary if you use things like that, I can't speak to it.
Only thing I noticed was for my bank's app, I had to enable "exploit protection compatibility mode" to make it function like it should.
I don't have any serious complaints about my 9a REALLY, but I'd prefer something with SD, headphone jack, and I'd REALLY kill for something much smaller. (but no fold, that stuff's for derpy weirdos)
I went Graphene a while back and can't be happier with it.
I'd still love to see a real Linux phone that really works and really has native Signal/etc apps but since buying a pinephone years ago to tinker with it, I'm not holding my breath.
If anyone here has fears/questions about installing/using it, I can give you basics. NOT an expert, but installation was the easiest thing I could have imagined, took MAYBE 10 minutes literally following their official guide.
Oh I'm with you there, but hydraulic hard lines and high pressure brake lines are thousands of times more rugged than electrical wires and cannot be rendered useless by software mistakes or operating system crashes.
The ABS controller, computer functions of a regular car can fail catastrophically, the vacuum system can be breached and made useless, but the hydraulic brake pedal is still capable of slowing a car to a stop.
Good luck