They're a tough sell for me these days. Some of it's because the standard humanoid races often feel like substitutions for genuine human diversity or an excuse to give a character "superpowers," (she can hypnotize the beasts of the forests without even having to learn how because her grandma was an elf, don't 'cha know). Sometimes they're also used to make a uniformly evil enemy who is evil just because their entire race is evil.
This is also why I would be hesitant.
It's not so much the races themselves. It's what they suggest about the rest of the book's content.