Diagnosis or not?

Hi I am new to the group - my daughter age 12 has been referred by CAMHS to be assessed for an autistic spectrum disorder. We are being asked whether we want to go ahead with this - I just wondered what the advantages and disadvantages of this would be. She functions well at school currently although is very withdrawn at times but at home we experience frequent violent meltdowns. I have read http://www.myaspergerschild.com/2014/12/advantages-and-disadvantages-of.html but wondered if anybody had personal advice.