Driver setup

I accidentally destroyed my Z stepper driver last week. Today the new part has arrived; an A4988 Chinese driver.
My previous drivers all have the 0.02 Ohms resistors. But..... the new one don't. It has two 0.01 Ohms resistors next to the processor. I've gone through the wiki and forums, found a lot of Vref formulas comparisons and other stuff but not what I am looking for: What should I do with the Vref? Should I change anything within Repetier setup or on the Ramps 1.4?
Also, can I use these different drivers together on the board?

And because I now have two new drivers (0.01Ohm) and two other drivers (0.02Ohm), is one better suitable for my Z-axis? In other words, is one driver more efficient in driving a threaded rod or belt?

Thanks in advance!

I'm sure you meant 0.2 and 0.1 ohm.
But anyway the 0.1ohm variant allows to set a higher current value than the others. That doesn't mean the driver can stand this current, so be careful not to overheat the driver.
It would be most suitable for the extruder, because it's often the stepper which needs more torque.
The Z-axis could also benefit from more current when you have two steppers running in parallel config. ( not recommended, but still common practice )
-Olaf

Edited 1 time(s). Last edit at 11/18/2015 03:39AM by o_lampe.

Thanks Olaf,
It's very clear, but just to be sure; The change in resistance just makes the tuning different, but I dont have to change the setup-files?

_{And actually I meant 0.02, but that doesn't mean I actually know what I'm talking about}

No the firmware is not related.
-Olaf