The GX AXS transmission was explained to be not an evolution in drivetrains but revolution in technology. It is expensive so I held off...until curiosity got the best of me and the teeth on my 1st generation Eagle GX required a cassette repalcement so I made the purchase. 1. Shifting under full load in the middle of an extreme climb is a joy!! 2. Durability - the components of the deraileur are beefy - high confidence. In spite of the thin 12sp chain, it is also beefy 3. Installation - SRAM did an outstanding job to install, calibrate - set and forget - VERY well done. 4. Quiet - 'nuff said 5. battery on the deraileur overcomes battery anxiety by having a replacement in saddlebag to overcome horror stories of Shimano DI2 users getting stuck in one gear. No question I would buy again and now I'm thinking of AXS for my gravel bike!