The Authentic Expression Technology (AET) sets the milestone in reproduction of sampled sounds. It allows acuratly reproduce dynamics and articulations without well know "jumps" in sound between different veloity layers.
On top to the traditional way of sampling of different volume levels of an instrument, AET captures specific spectral characteristics of samples and gradually apply them to another samples in real-time, allowing you to seamlessly “morph” between different instruments' characteristics/samples/layers.
AET is especially powerful applied to velocity trasitions of the same instrument and also works brillinat with solo instruments with sustained sounds - such as strings, brass, woodwinds, and choir. This is mainly because when one is playing long lasting sound could seamlessly fade with the Mod Wheel between different articulations (e.g. trumpet playing with and without mute) or volume/dynamic levels with different harmonics.
If you up for experementing the you would be glad to knoe that sometimes it is possible to merge the acoustic characteristics of different instrument such as the piano and celesta in real time, opening new area for creative sampling as it allows to create new kinds of hybrid instruments. Saying that you should not expect to have fab result when mixing completely different sounds like bass drum and stings. Well, as with any tools common sense applies.