Firstly, and least importantly, there should be a distinction between the words deflection and squirt. Most use them as synonyms, but it is worth being more specific.
Technically, deflection is the displacement of tip due to the orthogonal force of the cue ball upon the tip, causing the shaft to flex away from the line of stroke.
Squirt is the angular deviation of the cue ball from the aim line.
Deflection causes squirt. The MORE deflection, the LESS squirt.
The MORE the shaft flexes, or deflects, out of the way, the LESS rebounding potential energy is translated back to the cue ball perpendicularly to the stoke.
In other words, poking a bowling ball with English with a wooden baseball bat is going to throw its path off of the aim line more than poking it with a swimming pool float noodle.
Also, look at my avatar. The numerator and denominator are similar except for mass. The greater the mass of the cue stick (thickness) the less deflection, and the greater the squirt angle.
Another nice thing about the Z2 is how its made. The wood is actually a laminate of 10 pie-shaped pieces of wood with the same gain pattern. Therefore the deflection is consistent no matter how the cue is rotated in your hand, compared to single-piece shafts.
I am a beginner, at least I consider 3 years of pool playing the beginner level. I have a Z2 shaft on a McDermott butt. I have been playing for the three years with the factory shaft, and recently switched to the Z2. From the perspective of a beginner that hasn't been biased yet, the Z2 requires less pivot (front/back hand English) then other shafts, and makes it much easier to learn how to apply spin from across the table.
Now I pretty much feel like I can use spin for every shot if I want to. I'm not afraid of it. I even consistently apply top left and right on cue balls against the rail (compensating for swerve) and get out of sticky situations with more confidence than my other shaft, or other shafts.
So I guess the conclusion is that less front/back hand english is required. If you already have spent your life learning this compensation second nature, then stick with what you have. But this shaft is excellent for newbies.