It's a beautiful instrument for what it is, but absolutely not as much diversity or complexity as a piano. You can hear the entire music is at almost a single volume, more like a pump organ. The reverb you hear is from the room. I think it's an interesting and new way to hear Marais (which for me was the most successful of the pieces) but it's a period piece, the same way the harpsichord never made much past the 18th century.

note: Actually interesting to read the Youtube comments on this.