Haven't done this holiday, but have done 10 JY holidays.
With JY, you're never "alone".
Women tend to outnumber men, age ranges have been earlier 20's to late 70's (mainly 40+).
(don't let this put you off) group sizes smallest I've been on is 13 and largest 40.
Pick a holiday that appeals to you, and you will have a fab time.
Anna