I completely understand, although we are still in the early stages of figuring out DS (age 3 years 11 months). We are planning on doing some brief tests (KBIT & KTEA-II-Brief form) when he turns 4, but I can't quite get myself to make the phone call to set up the test. Right now I'm happy thinking "he just picks up on things quickly" instead of having a label.
Cognitively, I know that it'll be good to have some information. It will allow him to participate in enrichment weekend programs/summer camps that will introduce him to kids who are cognitively similar, and will provide some "data" for advocating for accommodations when he starts kindergarten. Emotionally, I'm hesitant to see numbers on paper. Like Deacongirl said, he's going to be the same fun, curious, active kid, but I'll have information that will let us know if minor accommodations within the classroom will be enough, or if we need to steel ourselves for battle with the school district.
And, of course, this isn't an issue I feel like I can discuss with anyone other than DH or this board! Many people will interpret it as complaining about being "too rich" or "too thin."
