I sent an email to Indiginus to explain the difference between their Resonator and IK's Resonator (since it also comes from Indiginus) but they never responded. Does anyone here know what the differences are? Is it just the GUI? Do they both use the same sound set? Do they both have access to the same articulations? Thanks,
You get keyswitches and articulations in IK, but no Indigenus GUI like you see in the Kontakt version. Kontakt also offers a solo mode and a chords mode.
The walkthrough videos on the respective product sites give the details, but here a couple of screen grabs that highlight the major difference in the GUI.