Interesting... for that shot, I aim like you do, but use the total distance to the hole - (minus) 1/2 ft power for every inch of slope shown at the cup. It's the same 'computation' I use on every hole that is on the 'down slope'. Probably is "six of one, and 1/2 dozen of the other", the way it works out.
When the cup is higher than my feet, I add about 1.5 ft power to the shot after figuring the initial distance, but I always use the 'rise height' at the cup for those shots, too.
Just goes to show you how there's different strokes for different folks - that ultimately work out the same. :)
BTW... I use the Redwood putter.
Great Post! Better than Excedrin!