I like
Suzanne more than
Susan, but I like
Susannah more than either one. Yes,
Suzanne is less dated than
Susan.
I know of one
Suzanne, my half sister through my father. I say I "know of" her rather than "know" her, because I never had a relationship with her and I've seen her maybe three times in my life, and at all of those times we refused to acknowledge each other's existence. It's a bad association, yet I still can acknowledge that
Suzanne is a nice name.
My youngest sister would have liked to name a daughter
Susanna or
Susannah (not sure which spelling she liked more), but felt that she couldn't because of our half sister
Suzanne.