i own kyma as well as an H7600.. though, i haven't played around with Vsig much (i'm on a mac, so only have access to the unsupported 3rd party version)… so i basically use the 7600 by editing the presets with the given controls.
kyma is an entirely different beast than the eventides.. capable of much, much more.. any type of spectral resynthesis, granular synthesis, morphing… combined with every other type of effect and synthesis… all at the same time or in combination…
while i'm sure an experienced Vsig programmed can pull quite a bit from the Eventide units, it simply doesn't have the algorithms (that i know of )to do things like resynthesis, convolution and granular synthesis…