Hi,
The instruments in VSO abrubtly begin and end at a particular note. For example, in the Normal Strings violas start immediately at C3; in the Normal Woodwinds clarinets immediately end at C4, leaving the flute alone.
With Vienna Instruments Pro one can make this kind of transitions smoother: instruments gradually enter or disappear at the end of their best range. It would be great if your preset were as smooth, even without giving the user the luxury of editing the range themselves.
The library would as a consequence sound absolutely perfect in any situation.
Paolo