Maybe it's just me but I find the buttons below the spacebar far more convenient to use together with the touchpad.
Yes, they are. The first generations of HP ZBooks had both the ThinkPad stick and the touchpad, so they had two rows of buttons, one below the space bar to be used with the stick and one below the touchpad to be used with the touchpad. ThinkPads usually have both the stick and the touchpad but only the buttons for the stick.
The ThinkPads have them below the spacebar. They are conveniently placed if one uses the little red stick, not so much for the touchpad.