Let’s break it down individually.
Both JX grinder and JX-Pro grinder shared the same burr design, the grinding result shall be similar.
However, the dissimilarity between these grinders is the adjustment design.
There is Top adjustment design of JX-Pro and the advantage of the adjustment is gives more click (40 > 30) as compared to the Internal adjustment design of JX grinder.
Total of 40 clicks per rotation, 4 clicks per number and 12.5 microns per click of JX-Pro grinder whereas 30 clicks per rotation, 3 clicks per number and 25 microns per click of JX grinder.
You could tell with the adjustment design of JX-Pro grinder allow you to dial in more and minor clicks for several brew methods, especially espresso.