Yes I agree Shimano was slow to get onto 12 speed. And yes XX1 and XO1 is excellent from SRAM. I think once you've experienced what it feels like to shift gears under load and doing so effortlessly with the Shimano 12 speed then you'll struggle to convince yourself that they are 2 years behind. I think you have the brands mixed up though, SRAM = Apple? A new XO1 cassette costs R6000, for that money you can get a new SLX 12 speed shifter, chain, cassette, derailleur and a new microspline hub. The SLX probably has the same or even better shifting. But in the end it does come down to the legs you are right...can't buy yourself up that hill