It's well-used, but I wouldn't say over-used. I love it, it's such a classic. And very, very pretty. I prefer
Elisabeth but
Elizabeth is almost as nice.
My favourite nns are
Beth and
Bess, although I love
Elsie and
Elsa too (my great-grandmother was an
Elsa). I
don't like
Libby - too much like baby-talk - and I find
Eliza,
Liza,
Liz and
Lizzie too harsh (although I like
Lizzy for the Pride & Prejudice connection).
Bessie and
Betsy are a little too babyish in the long term.
Ellie is good.
:-)