I have not had to tweak the EastWest samples much to get them to sound good – other than adding reverb.
The biggest advances in orchestral libraries are arguably * not necessarily with their sound, or sonic, quality, but in their ability to do some things faster and more realistically. For example, EWQLSO strings sound very good, but LASS, Cinematic Strings and other newer libraries are far better and more natural at legato playing than the old EW dxf method. Additionally, some libraries like LASS, Berlin Woodwinds etc., allow the composer to do accurate divisi writing. There are more velocity layers and more round robins, all of which enhance realism and speed up the work flow.
* However, I say “arguably” because some developers, like CineSamples (and the newer EW Hollywood series) have gone to great lengths to capture the sonic quality of specific sound stages. Spitfire libraries are renowned for their sonic quality, being recorded at Air Lyndhurst Studios.
BUT…depending or your style of writing all, or some, of these improvements may not be relevant.
_Michael