Few more observations. Only the trigger take-up, distance between fully forward and the "wall" is shortened. They did an excellent job with that. The trigger is essentially pre-pulled to the point where it's .5mm from touching the striker safety lever. If you pull the trigger from the sides, so that the trigger safety lever hangs on the frame, the strike safety lever is still untouched, so it's still a very safe system.
Break, reset, and over-travel are mechanically unchanged, but feel shorter and slightly heavier due to finger position having less leverage. To get an idea of how the break and reset of the HBI trigger feels, just pull your stock trigger with your finger higher up on the trigger than normal. I have a 5# Glock striker spring in there now, and I'm going to swap a 1/2# lighter striker spring to compensate.