The cross-grade price is great. I received my codes last night, installed, and gave it a spin as well as a comparison between VI and Synchron Player.
The articulation mappings are better now, and easier to use. I still wish the harpsichord had more stop combinations (and a solo 4' as well as 8= + 4' vs. only available in full tutti), but I guess there was no additional sample content to pull from, as there was with a few of the other older libraries.
I feel the Prepared Piano and Harmonium benefit the most from the SYNCHRON-ized treatment. I still have mixed feelings about the harpsichord, even though I have always ranked it amongst the best three in my collection (bearing in mind that I don't own the ones from Berlin).
I've never seen documentation on which model of harpsichord it is, so maybe that's part of it; it has release samples so that can't be why it sounds a bit wiry to me compared to some others. I suspect it's the exact character of the specific model sampled, as harpsichords vary quite a bit. So I do hope a future Synchron Harpsichords product will eventually arrive, with multiple models sampled!
Harmoniums vary significantly as well, of course, and this one has a particularly pleasing and broad range of stops. I can't off-hand think of another one that offers this variety of sounds. But one needs multiple harmoniums of course, just as with pianos and harpsichords. Still, this one comes pretty close to covering it all. And the price is a no-brainer for this whole library.
While the sounds seems to be the same as the VI version, I like the fact that you can now launch Synchron Player and start playing with the harpsichord, with all the reverb and positioning already done. Being able to read the articulation/register labels is another big plus.
Something I really like is that two instruments that seem to be made for experimentation, like prepared piano and harmonium (Schoenberg loved it!) can now be processed by the powerful internal effects. I foresee yummy things with them.