Too early to say apart from the significantly improved load times, and other practical things like the new GUI (HSSE). I’m having some difficulty locating instruments … HSO was too “busy” with the drop-down menus, but in HSSE all the sounds are mixed up with the stock sounds so I’ll have to find some way in MediaBay to tag them.
I have a HSO project that I’m trying to recreate as a new project using HSSE and the HSO Instrument Set, but it’s slow because I’m not sure I’ve got equivalent instrumentation as a result of the names being changed, therefore I can’t give a definitive answer as to whether there’s sonically any huge difference – but what I’ve got so far is very, very good!
[EDIT] OK one way … when loading a sound into HSSE, set a filter “Any attribute matches HALion Symphonic Orchestra” – that will return a list of 110 sounds, making it a bit easier.