I've noticed a few changes in finish of the driveshafts on my first batch DEX210 vs. recent batch DEX210, but both have the same dimensions and it seems durability too (I did break one in a crash, but that was on my FWD Buggy when the driveshafts were binding because I took wrong measurements).
This also goes for the anodizing finish, the colour seems to differ a bit between different batches but in actual function they're the same.
Also, the later batches of 210 have some reinforcing on the rear shock tower (vertical brace between main body and the small rib that runs over the top of the tower).
On early batches some parts seem a bit more warped than later ones (my wheels were warped so badly I couldn't use them - which they set straight by immediately sending me replacement wheels). This probably happened under pressure to make the shipping deadlines around the release.
Other than that, I haven't spotted differences between my kits
