I have seen data that the majority of golfers aim left of their target. Also, according to the discussion of most putter head designs above, it appears the common "face-weighted" and "toe hanging" designs tend to open the putter face. This is what I like to call "arm chair research", but do you think the reason most golfers tend to aim left is simply a compensation to the fact that most putters open to the target when they are swung?
Would be interesting to test whether changing the balance would change the way people tend to aim. Curious on your thoughts here.