Isn't this position a bit weird? Doesn't when in aero-hoods or in the drops, and quite too easy to press by accident when the hands are in normal hoods position.
I'd prefer this. Shimano one is inaccessible in the drops, and requires stretching even if you're just in the normal hoods position. This is easily accessible in both. Doesn't require much movement of the the thumb in aero hoods position either. Also, given the size of the button, it's possible that's a rocker ... if there were 4 inputs instead of 2 that'd be amazing.
Main drawback I can see is that they're stating 34T max (hopefully it will do at least 36T). Also in going the 'easier' wired battery option, rather than tedious wireless patent dodging, they've made the inevitable gravel version much more difficult / limited, or rendered road / gravel versions mutually incompatible re: derailleurs ... a problem Shimano can probably relate to.