Hi Nick,
basically I have the same questions, I am a long time user of VSL and Vienna Instruments+MIRPro fits me very well. It is my "sound" and it took me years to build my workflow (as a hobbyist I have to say).
I already asked a couple of times about the future of my VSL libraries, but of couse, the answer was always: Try SYNCHRON.
Which I did and I tried the SYNCHRON version every now and then but I never could make it "sound" for me.
Pardon my POV, but it is like a too sweet of an ear candy, catering to the YouTube "Make me sound like Cinema BangBoomBang Blockbuster XY" and it locks me into a prefabricaterd sound. Of yourse I can tweak it, but then I can also tweak my other Vienna Instruments. MirPro is still my best sounding Reverb. And the SYNCHRON Player does not do well next to a MIRPro. In my humble ear experience.
I personally think it is sad that Vienna Instruments Libraries seems like a dead end street, while everything new forces you to use SYNCHRON, I would love to see as much innovation in VI Libraries as it is for SYNCHRON. Imagine what could have been done with the VIPro with some engagement into new releases. But that is obviously not in the VSL future.
On the other hand, that decline of new stuff for VI was a wake up call to take nothing for granted and I looked into new stuff from other vendors that I would not have checked without the (for me) foreseeable end of VI.
As a fan boy from day one, I think it is kind of sad to see, when the old stuff disappears. But the SYNCHRON is definitely not my sound for the future.
But as with any opinion, your milage may vary.
Too old for Rock n Roll. Too young for 9th symphonies. Wagner Lover, IRCAM Alumni. Double Bass player starting in low Es. I am where noise is music.