Well the idea behind a low deflection shaft so far as I am concerned is this:
To be able to shoot a long shot, use english, and be able to aim accurately.
And to my knowledge, there is not a *no* deflection cue/shaft.
So for me, the *right* deflection shaft is what I want. Or a low deflection shaft which has the pivot point in a place where it is easy to pivot from.
So I have a Meucci PP2 butt and a Predator 314 shaft. The pivot point of my cue is where my back hand grips the butt of my cue.
For a long shot where I want to use english, I aim dead center, then move my front hand left/right for english, then shoot and the cue ball goes to the same spot as it would with a dead center hit.
And I do this all the time. OB way down at end of table, I want CB to come back to left side of table, I aim dead center, then move my front hand to the left while keeping my back hand in place, then I make the OB and CB hits rail then comes back to left. (I have steering!)
So this solves a lot of problems when using english on long shots.
If I had a cue where the pivot point was further back (lower deflection cue), I would not be able to aim as I do above. Or if I had a cue where the pivot point was further up (higher deflection cue), that would not work well either.
If you have a cue where the pivot point is where your bridge hand usually is, that will work, however, sometimes the cue ball will be near the rail and you can't use a 10 inch or 11 inch (or whatever) bridge.
And players can and do learn to aim for long, medium, and short shots using english with a regular shaft. Someone who has been playing this way for years might have trouble switching to a low deflection shaft. But if you are fairly new to the game, then I think using a "right" deflection shaft might be a good idea.
And once you find a cue which works best for you, then stick with that pivot point from then on. (Don't go changing things as you will need to re-learn how to shoot when using english.)