In my eyes:
Looking at note A and doing well means that the map is quite easy for you because you don't need to sight read a lot.
Looking at note B means that the map is either quite fast or out of your comfort zone so you need to have a slight overhead to read before hitting.
Looking at note C means that the map is over 200-220BPM is a 5.5+ star maps or it is VERY VERY hard for you to play.
I have found that looking at note C helps me hit things I am not able to hit while doing A/B. It's kind of like playing hidden for me. Although looking at note A is the most simple way of playing accurately since you actually are looking at what you are supposed to hit.
Looking at note A and doing well means that the map is quite easy for you because you don't need to sight read a lot.
Looking at note B means that the map is either quite fast or out of your comfort zone so you need to have a slight overhead to read before hitting.
Looking at note C means that the map is over 200-220BPM is a 5.5+ star maps or it is VERY VERY hard for you to play.
I have found that looking at note C helps me hit things I am not able to hit while doing A/B. It's kind of like playing hidden for me. Although looking at note A is the most simple way of playing accurately since you actually are looking at what you are supposed to hit.