I think not finding out is only a good idea for those who really don't care. It's only a nice surprise if you get what you're hoping for or if you will be just as happy with either. Not finding out seems to me to be just a delay tactic when you do care--in which case, I suppose waiting to find out toward the end of pregnancy might be a nice compromise. I wish I could be one of those people who enjoys a surprise, but I know I'm not. So, I never would have considered not finding out.