Very interesting concept. I Googled it, and this is what I came up with.
"Face balanced putters are those whose face faces upwards when you
balance the shaft on your finger. This will mean that the center of
gravity is directly below the axis of the shaft. Basically meaning it
will straighten a putting stroke on the forward motion. This type of
balance will suit those who have a straight stroke that goes 'back and
through'.
Toe Balanced Putters
Toe balanced putters are
those whose toe was points to the ground when you balance the shaft on
your finger. This means the center of gravity is not directly below the
shaft axis. This type of balance will suit a player with a in to out to
in stroke.
Whichever style you prefer, you will find when you are
switching putters it is better to stay with the type of face balance
you are using as they require different types of strokes. However, with
all this technology, if a putter feels good to you then you should use
it, because the most important part of putting is confidence".
There seems to be a clear cut choice in real life. I'm not sure how WGT implements balancing into their virtual putters.