I have. I used it to create a dragon character that was cursed at a very young age to stay a whelp for the rest of her life. She is mature in everything but her appearance. It was hard to adjust the dragon type to fit a 'normal' race. But my dm gave me the cap of 16 rp points (the points you use when making the races) since Fletchlings have that much. So, I took away speed, darkvision and breathweapons and came up with a total of 15 rp points for the race.
So, I think it is a very useful tool if you want to do something new and out of the ordinary.