If you've read a lot, then it should be clear. The small differences between the bikes only matter when the differences between the riders are small. At the beginning level, the differences between the riders are much greater. You can do the math.
ie ride harder than the rest of the cat x's and it doesnt matter if youre tires are squared shaped. figured that.
for what its worth my next ride will most likely have a 52/39/30 with a 10-speed 12-27, feel that will prolly be the best compromise between races and hillclimbing