Worked fine. I'll probably buy my own AXS. Mostly it was about removing thumb fatigue. Sounds stupid, but I'd do 12hr+ MTB rides and the most painful thing on my body was my thumb/hand/wrist from shifting. If I stick aerobars on the thing for TD, AXS will make that a lot easier too.
Personally I found the shifting on axs to be great, every shift is just as good as the first (component wear aside) I got the GX and it's been durable.
Which bits?
I've run a SRAM AXS RD on my MTB without changing anything else (other than cable shifter obvs), ie. Shimano 12s chain and chainring.