I personally prefer a square toe (and duckbill). several related reasons (just my personal feel/opinion) ...
1) square toe gives more hitting surface area on bat,
2) it makes bat face look bigger giving me more confidence to middle the ball..
3) i like to feel my bat as a simple rectangle to hit the ball rather than a complicated shape with rectangle top and semicircle bottom..
4) my square toe bats generally ping better off the bottom than the curved toe ones..
5) feels very stable when tapping bat
6) more surface area when blocking yorkers/ driving full balls
(lastly, duckbill for pickup)