Raycast.normal vs collision.contacts[].normal which is better?

hello there. i am working on a endless runner game for rotating player according to slope angle i am using raycast but today i thought of another way of doing it using OnCollisionStay. i am already using this function for ground detection and slope detection. i made a vector3 variable and in OnCollisionStay set it equals to collision.contacts[].normal. it does work perfectly but in profiler showing Garbage collector about 20B. since i have heard that raycast is resource intensive and also i've noticed it. whenever raycast fires firerate drops from 60 to 59 ( i am using Finite state machine that's my raycast does not fire all the time only on few states). so my question is what is better raycast or contact.normal.