This is not real 'scientific'. Sorry.
I upgraded my front brakes in two stages, but didn't test (seat of the pants, or otherwise) after each stage. So I can't tell you what each modification has done. But I can offer an impression of the overall change, versus 'stock'.
I upgraded to braided-steel lines ($100), EBC HH pads ($75), 2009 GSXR-1000 master cylinder (new, $179), 2009 GSXR-1000 one-piece calipers (used, $279). I had to drill a hole in the right bar and heli-coil it (to mount the bracket for the reservoir. Note: I've got Heli-Bars and a 3/4" GenMar riser with a ZeroGravity Touring windscreen. Had to remove the tab from the right switch housing and move the housing outward about 1/4". Otherwise, no fitment or interference issues due to m/c and lever. It looked like the stock bars wouldn't have required moving the switch housing.) All other parts were just bolt-on.
As for braking power now versus 'stock', moderate (using three-fingers) brake-lever pressure is enough to lift the rear tire. This is without skidding the front tire. Also, I feel more in 'control' when it comes to brake-lever pressure versus rear tire lift versus stopping distance. I can brake very, very hard, and at no time do I feel like I'm 'on the edge' (in danger of losing it). The stock brakes were fine, but the current set up definitely gives me a greater sense of confidence. The brakes definitely require less lever pressure for an equivalent (to stock) level of 'stoppage'. If I was going to sum it up in a single word, I'd say the front brakes are now more 'powerful'.
One time I changed just the front pads, and went out to 'scrub' them in. I recall the front tire skidding pretty easily. The brake lever was like a light-switch in this. Suddenly, the tire would lock up and start skidding. Maybe this was the pads. I don't know. But certainly, with broken-in pads (now) and the described setup, there's no tendency for the front tire to skid. The rear wheel will lift, first. (Another data-point: The rear end is raised 1" with dogbones--aside: lot better feel in the corners with it lifted, and better feel with side loads (such as from wind gusts)).
The bike alone weighs 550# (closer to 750 with me aboard), so there's still a lot of mass to decelerate. But for less than 700 bucks, these upgrades were worth it, to me, and made a noticeable, positive difference in stopping distance, and brake-lever feel. Maybe the most important thing for me is I BELIEVE in the brakes. I never quite trusted the stockers, wrongfully, or not.