I use rubrics in my classes regularly and I do give them to the students at the beginning of the project/assignment. This way the students don't have to guess what I want for a passing grade or what I want for an A grade. (I teach high school.)

I also find them convenient, efficent, and fair for the grading process - this is HUGE when you have 120 of something to grade.

My DD in 5th grade also receives rubrics at the beginning of projects.

DD12, 7th. Dx'd ADHD/GAD. No IQ test. EXPLORE & SAT just miss DYS but suspect HG+