Perhaps because of my typing technique, I tend to find spacebar action to be a distracting factor when it's not the same as the action of all other keys, or at least alpha keys.
I guess the size of the bar, the shape of the top of it, and yes, the stabilizers obviously a lot of difference and not just the switch type. It breaks my rhythm as one way or the other I end up applying different force much of the time, then there's the awful 'thock' and my fingers getting bogged down.
There are days I wish I could have two spacebars each the size of a letter key… and I think once upon a time I did that on a board, for a while. Hmm… perhaps I should try that again.
Usually no such problem on rubber domes and laptop boards, scissors etc. Wonder if the problem would be less pronounced on a low-profile mech board with a slim switch.