After fitting the Spice and now Spice +, I chanced on this PDF from Phonak, covering the underpinning technology and features of the Spice system. Worth a read to get the gist of everything that is going on.
The extra refinement of Spice + seems to have improved the timbre and initial user acceptance of the aid too. From a dispensing point of view, you have to ask whether the level of technology now available exceeds what can be understood by the average wearer (and average dispenser) to such an extent that they will never fully utilise some/most of the features. Yet the aid is still just as susceptible to basic 'plumbing failures' - wax blockage, mic screen issues, condensation - as it ever was. Even the H2O versions claims about water-proofing come with a caveat that you can still block the filters and the receiver units.