I am an owner of both the older Symphony and Musica.
Why not add a 500gig or perhaps two 500gig external hard drives to your Musica? For $100 US you now have lots of storage for music.
You state that your Musica is less functional than the Olive O4. Please tell me in what ways the Olive O4 is more functional than the older Musica or Symphony's.
With my Symphony and Musica I can do the following:
Add external hardrives
Use an external DAC
Convert analog recordings to digital
Listen to Internet radio
Backup music easily in a non-proprietary system
Control them with a PC, Ipad or Iphone
Stream music from one unit to the other
Add music by inserting CDs or through the USB ports or streaming
All of the above and more.with the added benefit of being glitch and hassle free.
Even after all these years I don't see the newer Olives as being anywhere close to the capabilities of the older units.
The only thing that I can think of is that the newer Olives have a color screen and can show album art. As far as higher rez files, well I'm not convinced they are any better than Redbook.