Another point I will add is that even amongst three 8bph movements, you will still see differences in the sweep. I have a 4816 (21J movement 2813 with 8bph instead), a Swiss ETA 2824 and 2893 side by side.... the 2893 wins by a long shot, the 2824 is still somewhat more jerky then the 2893, but slightly improved when compare to the the 4813
I also have some vintage 6bph gen Rolex in my box that seems to run very smooth, as though they are 8bph watches.... so although the spec might be the same, you really can not judge the movement by the specs alone.
Typically, larger the watch ( = longer hand size), the jerks are more pronounced. I have quite a few 21J subs, they are 40mm across running 2813 21J. And they are pretty jerky when sitting next to other 8bph watches.... but by itself they seems just fine. 99.9% of the population either dont care and wont be able to tell