4Game

This is a summary of a Russian vlogger known for his lab work:

Improved rotator 4.01s vs 4.3s Gun Laying Drive (Tiger I)
https://youtu.be/0UNYjeK4D2s?t=179
Running max speed, stopping, measuring aim time

V Stab + Rotator 5.18s vs 5:27s V Stab + Vent (Defender)
Running max speed, stopping, measuring aim time
https://youtu.be/0UNYjeK4D2s?t=329
V Stab + Rotator 7.20s vs 7:22s V Stab + Vent (Defender)
180 deg tank rotation (both chassis and turret) + full aim (see vid)
https://youtu.be/0UNYjeK4D2s?t=358

I assume 10% Rotator and 5% Vent were used, it's not clear.

Summary:

• Gun Laying Drive is useless, V Stab is more practical (except some arties where Vent isn't an option).
• Rotator's 10% faster turning increases the aiming circle. Additional 10% stab there is to compensate for that.
• There is no noticeable difference b/w VStab + Rotator and V Stab + Vent setups. Vent gives you some extras, e.g. loading, but they mostly negligible (https://youtu.be/0UNYjeK4D2s?t=268)
• The above with bonned Vent with +8.5% instead of +5% makes more sense, mostly due to the loading speedup.
• While WoT UI claims VStab + Rotator gives +30% stab, that's not true. Read the disclaimer in the pop up. My calculations predict ~27%.

Credit: Barabekus on Youtube (map guides, lab tests, hints etc. but in Russian).
Pls subscribe or like the vid if you find it useful.

I try to follow EQ2.0 tests. If there is interest, I'll try to translate the results I find. Hope it helps.