RDT definitely needed for the DF64V. Not necessary on the VS3 Gen 2 but it is helpful. Bear in mind that the VS3 will generate the motherload of static grinds until seasoned with around 300g of beans. As an all rounder and with stock burrs the DF64V is definitely better due to the DF DLC burrs which are very tasty for espresso, milk based and even quite good for filter.
For the full written review including more detail, head over to www.tomsgrinderlab.com/varia-vs3/
TLDR version: 55 seconds grind time using medium/light beans and RDT. Very little mess!
Which one is more worth is as an all-purpose grinder, VS3 Gen 2 or DF64V? For both these grinders you need to use RDT I believe?
RDT definitely needed for the DF64V. Not necessary on the VS3 Gen 2 but it is helpful. Bear in mind that the VS3 will generate the motherload of static grinds until seasoned with around 300g of beans.
As an all rounder and with stock burrs the DF64V is definitely better due to the DF DLC burrs which are very tasty for espresso, milk based and even quite good for filter.