I balance with fingertips (or knuckles with veryheavy gasmodels). I am of the opinion that the optimal balance point can only be determined by flight characteristics - not the other way around. It is just a rough benchmark based on the designer's estimate or experience with the specific model(s) he flew.

I enjoy flat spins, so I tend to balance further back. But I am also pretty mindful of my fuel and usually land with 1/4 tank remaining or more. I've seensome pilots boast about how far back they keep theirbalance point - like it's a badge of honor - and then pop beads of sweat trying to dead-stick a squirrely model in after runningout of fuel. Stall atail-heavy model at low altitude trying to stretch a glide and you'll be brushing up onyour "I was hit" and "the windgot me" excuses.