BasementDwellers post just reminded me of something worthy of this thread:
I've completely changed my shooting style 3 times in the past 5 or so years. All changes directly affected how I visually perceived the shot.
The first change was getting pool shooting glasses. Before the glasses, I could only see the cue ball clearly, or the object ball clearly, or the pocket clearly. Only one item at a time. Never two or three simultaneously. Getting the glasses completely changed what I could see simultaneously, and hence my perception of the shot.
The second change was I bought Geno's dvd and switched to the method of head alignment and eye use that he advocates. I basically was aiming shots with different eyes now on particular shots, and with different head positions. It meant my perception of the shot changed quite a bit from what I was used to.
The third change was just a few months ago, I switched to a much higher stance due to back problems. Again, my perception of the shot changed quite a bit from what I was used to before.
In all 3 cases, I had to "relearn" some shots. They just looked different, and I had to just get a new "feel" for them by spending a few minutes on problem shots, and also just playing the ghost on my own to get a feel for the general change in my visual perception each change brought upon.
So here is the relevant part to this thread: In all 3 cases, it just took me about a week of playing to become completely comfortable with my new perception of the shot, and to have the same overall speed as before. My point is, at least in my experience, aiming and sighting are so simple, that 3 separate drastic changes in my situation, took only 1 week to feel completely comfortable with. I just can't understand how someone can say it takes months or years to see the right shot line.
It is amazing how a player's "view" can change over time, even day to day. I know that when I'm playing well I actually see things slightly differently than the days when I'm not. It's actually kind of hard to describe but in particular I see the relationship between the CB and my cue tip a little differently (stay away, Geno, not talking dominant eye here

Getting back to your post, I agree with what you're saying about "sighting in" the shots. For me it takes two or three days, maybe three hours a day. It certainly doesn't take months.
Lou Figueroa