Just personal taste, I’ve taken them out of mine but I used to use them, I prefer feel to stiffness.
It’s interesting though, people make a lot of noise about stiffness and power transfer and all that but when offered the choice people seem to go directly to the least stiff option. Every review of the AMs I’ve seen has said the same.
sold five tens as I hated the lack of feel from having a stiff sole (no point having infinite grip if you need blind faith the grip exists) and have just got AM40s. Wont be using the inserts as Ive never suffered from foot ache using flexible old Vans on 6hr rides, but given they come with the shoes you can try them out for no cost.