They have more such demos, but: http://www.pianowave.de/e-bechstein.htm This Demo-Version is playable in the full dynamic and chromatic range. So you can get familiar with the most important aspects of such a software instrument: The sound AND the playability! - The only limitation is that all samples except the middle octave and all Cs fade out after one second. And for the rest, a plus: - The sampling frequency was reduced to 22kHz. Dunno if it's worth adding to the Master List, either...
Sadly a bit limited and there are so many other good free pianos out there like that new 5+gig Steinway. I guess it would work for a staccato piano. Free Bechstein here. No limits. http://sonic-cat.com/pop-piano-free/