that is correct...OEM discs are designed for the track as well and durability. you can not go wrong with OEM.
i would argue yes and no on both counts (OEM and get what you pay for). Sure, it will probably be good, but is it worth that money? no. its OEM tax, and they take the piss.
Not only that, but it was OEM that was on there and warped up after 15k miles (gentle miles). mechanic said there was still heaps of disc left (>50%). That's bullshit if you ask me. OEM money should have a product that can last the distance, especially when its not been beaten on. Or least put a serious warranty on them.
Beyond that, I know a lot of products across a range of vehicle applications where OEM is inferior to aftermarket and still asking twice the price.
It's not a hard and fast rule to be sure
fyi.....you get what you pay for. Brembo parts, well that is some serious money for seriouse performance.
Sure, I hear good things. But for disc rotors im not sure again the price would be massively worth it (master cylinder and callipers sure, that's some serious engineering and brembo are the top). But again they have a "name-brand tax", they can charge extra so they do. Id say there would be very little in it between brembo discs and say MetalGear or EBC discs for a lot less money. Especially for my purposes (80% street riding, 15% fast street, 5% track-day) its unlikely id make the most of the higher end products and their higher performance.