It's pretty and sparkling and romantic. Makes me think of the doomed Tsar more than
Santa Claus.
Nicky on a boy would be pretty cute, I think. Plain old
Nick is not great, but
Nicholas is handsome. I don't think
Nick can be avoided, but
Nicky probably can be. I never knew a single
Nick who was ever called
Nicky, at least in my hearing.
I like
Nikolas too, but not any more than
Nicholas.
Nicolas is ok... That one is pronounced differently I think, right? It doesn't have the same glittery shine that
Nicholas does.