Just out of curiosity, why is balance important? This is the first time I've ever even heard it brought up. You don't ride a bike balanced on a finger, a bike has two contact points on the ground and a much heavier object (the rider) positioned on top of the bike which will dramatically alter the center of gravity and balance you've sought. Hell, pros even stick metal rods in their top tubes to make UCI weight regulations, so I'm curious as to why you place such importance in it?

Either way, until you're on the slopes of Ventoux or Mount Evans, weight of the bicycle has little effect. I made a big change on my CAAD going from the stock Shimano wheels to Eason EA90's. The drop in weight was about .5 pound, probably more considering I changed to GP4000 tires as well. I don't feel jack difference, even when climbing. What I do feel a difference from is bumping up my riding mileage and lengths of rides.

I think many who have posted in this thread would agree the weight obsession and tinkering is a hobby in itself as much as cycling which is cool, but as others have mentioned, let's try to keep things in perspective when extolling the virtues of 60 gram differences (about .14 pounds) in cranksets and brake sets.