`transition: none` breaks pages relying on the "transitionend" js event (edit: and i guess the other transition-related events i forgot about), i noticed logging into google wouldn't work with it (it wouldn't hide some gray overlay)
here's what i use instead:
/* forgot if this was needed but i think using !important here broke something */
transition-property: none;
/* maybe not needed */
transition-delay: 0!important;
/* non-zero to support "transitionend" event */
transition-duration: 0.0000001s!important;
/* possible tiny optimization */
transition-timing-function: linear!important;