I'd say it's less piano-oriented than her first albums, maybe with the exception of "Scarlet's Walk", which is overall a rather quiet album.
The studio album I've listened to the most is "From The Choirgirl Hotel". On it's successor "To Venus And Back" you find hardly any clean piano-parts, but mostly electronic (if this is the right word) sounds. Actually, it's a double album. In addition to a studio album you get Tori's fist official live-CD featuring mostly songs from her first three albums. Most of the live versions sound more or less different from the original studio versions, maybe also due to the fact that Tori likes to improvise when playing live. E.g. the live version of "Waitress" is more than 9 minutes long.
Her last two albums "The Beekeeper" and "American Doll Posse" are more heterogeneous than their predecessors and in my opinion they are, just like "Scarlet's Walk", too long, i.e. I find it somewhat tiring to listen to the entire albums in one go. I like "American Doll Posse" better than its predecessors, maybe also because it features some of Tori's most rocking songs ("Teenage Hustling", "Body And Soul"), which doesn't mean the softer songs are bad.
I think you find uncountable live-clips of Tori on youtube, but since Tori's live versions can sound very different from the studio versions of her songs, it might be difficult to tell whether you'll like the studio versions as well or not.