Substantive Mechanical Difference Between Tatula Range vs Zillion/Steez A

Hi guys,

I currently own a Daiwa Steez A 1016 baitcast reel, and a Daiwa Zillion TW HD 1520.

Given that these are really expensive reels, I was debating downgrading to an 18 Tatula 100H an 18 Tatula 200H respectively.

I am not very mechanically minded, however I am trying to cut through some of the marketting puff, and develop a substantive understanding of precisely what I am "giving up" in downgrading to these slightly cheaper (however still good quality) reels. I am far from a gun fisherman by any means, so I am confident that the Tatula models will be more than adequate for me, even if a little less "smooth" or slightly shorter-casting. I feel like creating threads like this with "benchmarks" demonstrating what substantive "upgrades" come with each reel model from base models to Steez would be super useful for reel-buyers, but as far as I know nobody has compiled such info. 

So far my understanding of the difference between Tatula and Zillion/Steez is:

Worm Shaft Collars (rather than worm gear bearings). Is anyone able to articulate how much difference this is likely to make in functionality? What aspects of fishing this affects?

Spool shaft (vs free floating spool). Again, what is the impact of this?

Heavier spool spool - more energy to start spool rotation, slightly shorter casts.

No Handle Knob bearings - Steez A uses plastic collars also. 

Different drag - single drag washer rather than Carbon Drag stack. Results in less maximum drag. Potentially less smooth also?

Brass gears in the Tatula, Aluminium gears in the Steez A/Zillion (both still have some plastic internal components, to my understanding).

No Magseal in the Tatula. 

Same TWS, same magnetic cast control systems, same handles/knobs/body material (full aluminium frame in Tatula).

I would love to hear your opinions on any other substantive differences between these mid-range versus high-end reels, and how you feel these differences "manifest" in the actual fishing experience i.e. smoother, cast further, more durable in what ways (corrosion resistance, can cast heavier baits, less prone to breakage, overall longevity without breakage). How do you feel about the "value" offered by the high end zillion/steez models, do they justify the price increase (to you)? I feel like it's a bit of a trap for newer fisherman to want the "best" gear available, and the manufacturing brands don't necessarily make it easy for the average joe to develop an appreciation of what they're paying for between each price point beyond cosmetic increases, and peace of mind that they have "the best".