There has been quite a bit of discussion over time about sampled instruments and VSTi\'s, and I feel as though many people are not very clear as to the differences between the two regarding quality of sound, if there should happen to be any differences at all.
In order to clear up any confusion on this subject, let\'s for example do two different things with the EXACT same samples for an instrument... such as... number 1, make a native HALion, Giga, EXS24, Kontakt, etc., sampled instrument with these samples, and number 2, let\'s make a VSTi sampled instrument with these same exact samples. When you play any of the software sampler versions of this sampled instrument, and then play the VSTi version of this same sampled instrument, they will both sound EXACTLY the same, because in both of these situations these exact same sampled audio files are being streamed and played from the disk, or loaded into and played from RAM, whichever the case may be.
The only things that will effect the sound of playing back these sampled instrument audio files in either of these two situations, (other than the use of filters, effects, etc.), is your audio hardware (A/D\'s and D/A\'s) and audio monitors.
Regarding the advantages of sampled instrument CD\'s or DVD\'s in native HALion, EXS24, Kontakt, Giga, etc., or the advantages of VSTi\' instruments, it is \"six one half dozen and the other.\" With sampled instrument CD\'s and DVD\'s, you load them into a sampler program such as any of the ones mentioned above, and with VSTi\'s you insert them on an audio track in whatever host audio program you are using that will support VSTi\'s, which most audio/midi programs do these days one way or the other. From my perspective, either of these methods for playing back sampled instruments are equally satisfactory, and one is not better than the other.
Both soft samplers and VSTi\'s have programming features and effects, though a software sampler will usually have more in the way of effects and programming features options than a typical VSTi. VSTi\'s generally only provide basic effects and features that are useful for the particular VSTi instrument.
In conclusion... when making a decision as to whether to go with sampled instrument CD ROM\'s or DVD\'s in a software sampler format, or VSTi\'s, it gets down to the quality of sound of the sampled instrument, whether it be on sampled instrument CD ROM\'s or DVD\'s in a software sampler format, or as a VSTi. Most people end up having both, in order to get the quality of instrument sounds they are wanting.