I have been playing with Inspire 3 for a few days. Like some of the new features but it seems unfinished.
The Surround Town tabs are half new and half old and the new features are going to be exclusive to the 1600 and Zon.7 products (Noise & Speech in Noise).
Speech mapping is very nice, though it is not included in the 200 (2Ch/8Band basic model) model of the Destiny and as a result it has had SoundView removed.
So far as I can tell there is no need to upgrade the firmware on existing 1200/800/400/200 models as there really are not any new features coming to those models that are not half-finished UI improvements.