Please assume that watch case thickness is not a significant factor. I'm also unconcerned about the marginal difference in accuracy between these two movements at the given grades.

I'm relatively new to watch coveting and trying to understand the practical differences here. Thus far, I have gathered that a top grade movement from ETA is going to have higher quality materials for several key components compared to an elaborated grade; the barrel spring, shock protection system, pallet stones, balance wheel & hairspring, and the regulator mechanism.

So, if a top grade 2824 is made with higher quality materials than the elaborated 2892, wouldn't it be considered a higher quality movement? There must be other factors to consider that I am simply unaware of.

Also, if someone could explain why the 2824 has 25 jewels and the 2892 only has 21, I would appreciate it. This indicates to me that more jewels doesn't necessarily equate to better movement, so what good does knowing the number of jewels do for you when trying to evaluate one movement against another?