From a 600ish Fargo level player:
I aim with a combination of ghostball visualization and OB/CB overlap intuition while standing, then drop straight into the shot. I don't focus on any singular point on the OB at any time, since it doesn't matter for me, I just focus on the OB as a whole, with the peripheral image of the CB (and the cue) contained in the same visual image. OB/CB overlap being the key thing while down, I know the shot is on if this overlap "feels correct". This method applies for me no matter what kind of spin I use. My stroke straightness comes from always stepping into the shot the same way and aligning myself properly with my body. Chin and chest cue contact helps a lot with this. In other words, the direction/location that your cue must be is always exactly the same relative to the shot image, no matter what type of shot you are facing, and I find this correct direction with a bodily alignment method, which doesn't require looking, or even knowing, the exact point you will hit on the OB, as long as the visually perceived overlap is correct.
So, to answer your question directly, if someone measured the exact point my eyes are focused at, it'd probably be somewhere near the OB, but this point would be insignificant and not alter my success rate for pots. In terms of potting accuracy, the largest benefit for me at looking anywhere near the OB and not the CB is the clearer observation of staying still. Looking at the CB, if you slightly move your body by accident, you might not notice it, but by looking at the OB and being hyperfocused on the OB/CB overlap, the slightest of movements will be noticed. OB last is also obviously good for many other purposes too that aren't related to shooting staight, most obvious and large benefit being that you see the whole picture of what you are doing which helps with speed control and more.