the move from d-pad to analog sticks took a bit of adjustment too...
i'm of a mind that i can't can't really make a judgement on the controller until trying it (and if Valve has any brains there will be little booths popping up that let people do just that)
but i can see how it might feel pretty good and natural if it can truly track the tips of your thumbs with a high level of precision/accuracy.
if you picture how somone might mime using a controller...hands cupped, thumbs wiggling...it fits that well enough but this has a layer of potentially problematic mechanical parts (ie the sticks) removed...if it truly does work well...if the "trackpads" really are waaay in advance with those we might casually/lazily equate them with...it may be very good indeed...
regardless as an idea it still holds weight for the future because of that removal of mechanical parts angle...even if it doesn't satisfy everyone now with this iteration, doing away with the sticks still makes a lot of sense going forward...
to my mind, despite how...emblematic?..."sticks" are to gaming and gamers (and they are), this potentially has a bit of the move from ball to optical mice about it...
edit - consider also the fact the control surface/point is curved in a manner that actually follows much more closely the natural track of the movement coming down onto it from the axes of the joints in our thumbs (unlike thumbsticks which because they move on a separate axis of their own actually do the opposite) imo this design possibly has the potential to be much more comfortable in use than what we have grown accustomed to. simplistically put that bowl/cupped shape will require less "stretching" and "folding" of the whole of the thumb.
on a personal note i actually have "problems with hands" due to working in the "trades" for years and i kinda want to try one of these out due to the fact they may actually be far more "ergonomic" than what we're used to and thus hopefully kinder on my hands when setting about a decent gaming session that requires a controller.
tbth i still kinda prefer using a d-pad when it occasionally pops up in my gaming because, as i mentioned, thumbsticks require that "stretching" and "folding" of the whole of the thumb and maintaining a sort of "balancing on the axes of the stick" touch (as opposed to a sort of more planted actually "resting on the controller" touch) which sadly often makes often makes my hands hurt quite badly now
one way of looking this design is in terms of being more akin to an evolution of the old d-pads rather than the intermediary of "analog sticks" because it kinda seems much like a "digital d-pad" but with the direction that the "d-" stands for now being tracked in a full "analog like" range, subtlety and speed of motion and i suspect that'll probably be a bit like what it feels like in use "in your hands"...assuming the technology "works" ofc...