The articulation of your playing will really translate – and if you have a good enough MIDI controller, it can be almost as realistic as the real thing. 1 is an upright piano plugin that offers a tremendous dynamic response.
If you need a versatile free piano VST that is easy to use, this offering from 99Sounds is well worth looking into. Upright Piano also features key release samples and envelope controls for adjusting the attack and release time.