HI DAW Monkey,
Excellent posting.
Just adding my thoughts to the postings replies you have from the PG forum gurus.
You say :
is there a product, at all, that just plays your score, created in Finale or Sibelius
I have Finale and Sibelius. They have their own built in sound libraries which are very extensive that play the music scores you create. Therefore, there is no " tweaking " involved.
There are also some very excellent VST instruments.
If it's only a piano sound you are looking for I personally recommend Neo Soul Keys® from Steinberg . Combining faithful recordings of vintage keys with state-of-the-art technology employed in Steinberg's engines and effects, Neo-Soul Keys proves to be the ultimate electric piano experience. And of course you can just play the Neo-Soul keyboards just out of the box or you can tweek them.
Or Steinberg's , The Grand 3, presenting a premium collection of various piano models including three concert grand pianos.
I would also like to comment that it also takes a good sound system to make your ears happy rather then the low cost built in in computer speakers.