Planning to replace my rear brake discs soon. Read that slotted ones help clear dust and gas better, especially if you do occasional spirited driving. But are they really noticeable over plain ones, or just marketing? What's your experience?

Slotted discs do make a difference, mainly in keeping the pad surface clean and reducing fade on longer descents or hard stops. I switched from plain to slotted a year ago on my daily driver, and braking feels more consistent now, especially when wet. Not night and day for city use, but definitely less squealing and better pedal feel. Found a good selection online at https://elartcom.eu/categories/brake-discs-2 - they have both standard and performance styles at reasonable prices. Paired them with semi-metallic pads, and no regrets so far. If your car sees any twisty roads, I'd say go for it.