<p>Assuming you have a high quality printer with a fast processor, will you see a noticeable improvement by upgrading from 16X/32X microstepping drivers to 64X/128X microstepping drivers? (e.g. smoother surface finish).  In what ways do they perform differently from the more common 16X or 32X stepper drivers.  I'm thinking the RAPS128, Silencioso, and Trinamic drivers vs the DRV8825, A4988 and A4988.</p>

Prints benefit from higher microstepping in two ways:
Noise level
Using microstepping reduces noise from your printer's operation.
Print quality
Using higher resolution microstepping does not increase the physical accuracy of your prints meaningfully, but it can reduce surface artifacts such as
moire
.