If you do have a problem with your brakes:
Are you getting brake fade? Yes or No
Can you lock the brakes at any speed? Yes or No
Do your brakes lack "feel"? Yes or No
Do your brakes work consistently? Yes or No
Exactly what is your braking problem?
If you do not...
I think (and am sure if wrong will be corrected) that all Shimano 4 piston calipers from MT420 to BR-M9120 (XTR) have the same size pistons so all work pretty much the same, and all have ceramic pistons with the exception of MT420 which have organic pistons. I have BR-M6120 (Deore) calipers with...
I'm 78kg ready to ride on a relatively heavy (25kg) 2022 alloy Trek Rail with Shimano SLX brakes with organic pads and Swissstop 220mm rotors. Great feel, stops from any speed, never get brake fade. When hitting 20+ mph downhill of course I'm sitting on a directional missile, it's the nature of...
You have effectively been told by the bike manufacturer that the product is not fit for the purpose for which it was sold. Return the bike and demand a full refund.
£19/24 for a crankset that works is a bargain. If they clear the motor cover then you're good, why mess with them? You can spend £big to get Pinnd or Hope logo on cranks but will they work any different? Nope.