Feel free so stick those useless SD cards to your brand new R5 or R6. I am not going to pay close to A$5000 on R6 or over A$7000 on the R5 and use a SD card that cannot realized the full performance of the camera. Just stupid!Check out the full specs before posting such (useless) comment.
It's really not useless, especially for the R6.
Of course it is always best to have the fastest and have everything unlocked and the best performance for burst shooting.
But for those who don't need it, might as well save up some money, it is not a small difference in price.