I read Piers Anthony when I was a teen as well, and enjoyed it, but there is a lot of creepy subtext that I missed at the time so that I would not recommend it to my son.
Stuff like:
-relationships between young female teens and much older men (Adept series),
-an obsession with the underwear of female teens (one of the Xanth series is literally called ‘The Colour of her Panties’, but it is constant in Xanth),
- the idea if a young woman is attractive or teasing, a man is exhibiting extraordinary self-control in not sexually assaulting her (Adept series again)
Overall, knowing that a middle-aged man wrote these novels really makes it feel skeevy in retrospect.