Hello Nicholas!
I'm sorry that you are not satisfied at the moment. Please be aware that working with the Vienna Instruments is a learning process. In order to make your scores sound great you will have to put some finetuning work into them. The first steps would be adding articulations. For example, use staccato marks for staccato articulations and slurs for legato. You will find all the details in the "Optimizing Sibelius Playback" manual. Maybe it also helps, if you just play around a bit with a MIDI keyboard with the different articualtions.
If you have any concrete questions, don't hesitate to ask.
Best regards,
Andi
Vienna Symphonic Library