I don't use specifics but like you I do give rough measurements on somethings and not on others, like everything you need a happy medium. I described one character as: She was small, several inches below his nearly five and a half feet, thin and delicate looking and he knew she couldn't be more than a hundred pounds, if that...
It gives the reader a rough outline and lets them fill in the details so that the character will feel more real to them since they had a hand in that character's creation. Going to the tape is ussually too much" She was 5 foot 1 inch, wieghed 104 pounds, C cup breasts...blah...blah...blah
Makes it sound like an APB.
I do laugh when writers tell us exactly how long their male character's penises are, do guys actually measure their junk? Cause in nearly fifty years I have yet to do that...seems sort of wierd to me.
So in conclusion There's nothing wrong with using numbers to describe a character, just don't go overboard...but that's just my opinion.
I don't know what that means, but after reading it I wanna take a shower!