It's certainly less popular than
John but it's been in the top 100 (in the US anyway) for about twenty-five years. "Too common" is a matter of personal taste, I think, and I'd generally aim for a name that's outside the top 100. Of the top 100 names though
Ian is definitely one of my favourites.
My fiance likes more common names though and if we were really in a dispute, I could concede to
Ian.