I'm probably one sort of representative of the extended market VSL are now aiming to encompass - I'm not a pro composer and have somewhat limited computer assets. But I love to get under the hood and enjoy the manifold nuances possible with Silent Stage recordings in VIPro. I also use Synchron but don't as yet have any original Synchron libraries (except EO 2.0), nor MIR, and usually make my Synchronised library instruments as dry as possible. I have certain other, very recently released, truly excellent facilities for sound spatialisation which now I couldn't do without; they enable me to place Silent Stage instruments on a live stage with superb 3D precision and exquisite reverberant beauty.
Yet I'm also keen on big multi-mic live sound stage sample library recordings, and to date my best experiences in that regard come from using George Massenberg's astoundingly good and ground-breaking recording of Superior Drummer 3's core library at Galaxy Studios (with up to 11.1 channel surround capabilities). I believe percussive and plucked instrument sounds benefit the most from multi-mic live stage recording. Alas, to really enjoy the full splendour of big sound stage orchestral libraries I'd need some serious additional computer assets. (Well I'm dreaming of building a couple of VEP slaves with the latest lightning-fast PCIe-Gen4 slots and SSDs to match.)
While I'm up against these limitations they serve to make me more determined, more resourceful and more inventive in order to get the very best I possibly can out of what I have at hand. And these days the possibilities are HUGE. VIPro is in my view still one of the best enablers out there.
On my reading, all the viewpoints expressed in this thread have solid validity. But I'm guessing some substantial degree of resolution and unification of these viewpoints may well come when Synchron Player Pro eventually arrives.
(Oh and by the way, Paolo, I adore some of Messiaen's works and I certainly admire and respect your keen ambition with Quatuor. However I'd say to Mr Messiaen about Quatuor:- 'Mais mon ami, pour le chant des oiseaux, I'll stick to listening to live Blackbirds and Nightingales and all our other friendly feathered maestri out there.' lol - forgive me, just teasing.)