I have NEVER met an
Abigail who went by her full name. It's always shortened to
Abby. I agree that "
Abby" sounds young, and it definitely sounds cute (too cutesy for my taste), but I don't find it fresh (I've heard it way too often).
It'd be a nice change to see an
Abigail. Yeah, it's kind of boring, but I like the "gail" sound, and as you say it is classic.