On my last car (G31 540i) it was irritating because the car would coast sometimes with the engine shut off. When picking up the throttle out of bends, this would lead to a delay, which almost felt like a flat spot on the throttle. It also used to occasionally shut off just as I was looking to pull away at roundabouts and junctions, which lead to a slight delay, meaning I’d push the throttle down harder (because I’d committed to a gap in traffic and wanted to get moving) which would then cause a very jerky acceleration.
On my current car (F90 M5 Comp) it’s far less obtrusive, but it kicks in when the engine isn’t that warm, which I don’t like. I want the car to come up to temperature properly. I’ll use it if I’m sitting in a lot of traffic, but for just normal driving around town (where my stops are fairly minimal) it gets turned off.
Yes, it’s convenient and helps with emissions and that’s great, but if you’re not stopping for very long at a time, it can be very annoying.
I’ve had runflats on a few cars.
Our last car (G31 540i) had them. Ride was quite firm, not terrible, but would have been far better on regular tyres. Hitting small unseen potholes or joints in the road sounded awful - there was just no flex in the sidewalls at all. Actually cracked a rim on a pothole the week before we traded it in.
Current car doesn’t have runflats and is a million times better. It feels far less skittish over bumps (granted it’s an M5 vs a 540i but you can feel the difference the tyres make) and I don’t wince every time I see a bump in the road. I’ll avoid runflats like the plague in future.
Depends what is important to you - if you do a lot of remote driving and are worried about getting stranded they might be worth a gamble. If you enjoy comfort or spirited driving, I’d give them a swerve.