Virtual Playing Orchestra and SFZ files
I was delighted today to finally come across a genuinely high quality set of SFZ sound files that you can find and download here: http://virtualplaying.com/virtual-playing-orchestra/
Unfortunately, unlike using a soundfont, where you simply load the soundfont and the entire list of instruments in automatically loaded, you must load each SFZ file separately into the "Zerberus" portion of the synthesizer. That makes for a lot of work, and in addition, MuseScore "crashed" at one point when I had loaded about 1/2 of the SFZ files into it. I have not tried since to load the ENTIRE set, and have only loaded a subset that I needed for a particular piece of music, which worked fine.
The sound, however, is superb, and well worth the added effort, in my opinion. It blew me away particularly with the strings. You can hear an example of it that I uploaded at
Like I said, the best thing to do is to pick and choose ahead of time the instruments you want to use for a particular piece so you can upload to Zerberus just the files (instruments) you need to turn your music into a high quality MP3 when you are finished.